Merge remote-tracking branch 'origin/v8/dev' into netcore/dev

# Conflicts:
#	.github/workflows/codeql-analysis.yml
#	src/Umbraco.Core/CompositionExtensions.cs
#	src/Umbraco.Core/Constants-AppSettings.cs
#	src/Umbraco.Core/GuidUdi.cs
#	src/Umbraco.Core/Models/PublishedContent/IPublishedContent.cs
#	src/Umbraco.Core/PublishedContentExtensions.cs
#	src/Umbraco.Core/Routing/DefaultUrlProvider.cs
#	src/Umbraco.Core/Routing/UrlProvider.cs
#	src/Umbraco.Core/Routing/UrlProviderExtensions.cs
#	src/Umbraco.Core/Runtime/MainDom.cs
#	src/Umbraco.Core/Services/IRuntimeState.cs
#	src/Umbraco.Core/StringExtensions.cs
#	src/Umbraco.Core/Sync/ApplicationUrlHelper.cs
#	src/Umbraco.Core/Sync/DatabaseServerRegistrar.cs
#	src/Umbraco.Core/Sync/IServerRegistrar.cs
#	src/Umbraco.Infrastructure/Media/EmbedProviders/Instagram.cs
#	src/Umbraco.Infrastructure/Models/ContentBaseExtensions.cs
#	src/Umbraco.Infrastructure/PropertyEditors/NestedContentPropertyEditor.cs
#	src/Umbraco.Infrastructure/PropertyEditors/ValueConverters/ImageCropperValue.cs
#	src/Umbraco.Tests/Misc/ApplicationUrlHelperTests.cs
#	src/Umbraco.Tests/Routing/UrlProviderTests.cs
#	src/Umbraco.Tests/Routing/UrlsWithNestedDomains.cs
#	src/Umbraco.Tests/TestHelpers/TestObjects.cs
#	src/Umbraco.Web.UI/Umbraco/Views/Default.cshtml
#	src/Umbraco.Web.UI/Views/Partials/Grid/Editors/Rte.cshtml
#	src/Umbraco.Web/CompositionExtensions.cs
#	src/Umbraco.Web/HtmlHelperBackOfficeExtensions.cs
#	src/Umbraco.Web/ImageCropperTemplateExtensions.cs
#	src/Umbraco.Web/Models/Mapping/ContentMapDefinition.cs
#	src/Umbraco.Web/PropertyEditors/MultiUrlPickerPropertyEditor.cs
#	src/Umbraco.Web/PublishedContentExtensions.cs
#	src/Umbraco.Web/Runtime/WebInitialComponent.cs
#	src/Umbraco.Web/Runtime/WebInitialComposer.cs
#	src/Umbraco.Web/Templates/TemplateUtilities.cs
#	src/Umbraco.Web/UmbracoContext.cs
#	src/Umbraco.Web/UmbracoHelper.cs
#	src/Umbraco.Web/UmbracoInjectedModule.cs

.github/CONTRIBUTING.md

@@ -102,10 +102,11 @@ That said, the Umbraco development team likes to follow the hints that ReSharper
 
 The Core Contributors team consists of one member of Umbraco HQ, [Sebastiaan](https://github.com/nul800sebastiaan), who gets assistance from the following community members who have comitted to volunteering their free time:
 
-- [Anders Bjerner](https://github.com/abjerner)
-- [Emma Burstow](https://github.com/emmaburstow)
-- [Poornima Nayar](https://github.com/poornimanayar)
-- [Kenn Jacobsen](https://twitter.com/KennJacobsen_DK)
+- [Nathan Woulfe](https://github.com/nathanwoulfe)
+- [Joe Glombek](https://github.com/glombek)
+- [Laura Weatherhead](https://github.com/lssweatherhead)
+- [Michael Latouche](https://github.com/mikecp)
+- [Owain Williams](https://github.com/OwainWilliams)
 
 
 These wonderful people aim to provide you with a first reply to your PR, review and test out your changes and on occasions, they might ask more questions. If they are happy with your work, they'll let Umbraco HQ know by approving the PR. Hq will have final sign-off and will check the work again before it is merged. 
@@ -128,7 +129,7 @@ In order to build the Umbraco source code locally, first make sure you have the
   * npm v6.4.1+ (installed with Node.js)
   * [Git command line](https://git-scm.com/download/)
 
-The easiest way to get started is to open `src\umbraco.sln` in Visual Studio 2017 (version 15.9.7 or higher, [the community edition is free](https://www.visualstudio.com/thank-you-downloading-visual-studio/?sku=Community&rel=15) for you to use to contribute to Open Source projects). In Visual Studio, find the Task Runner Explorer (in the View menu under Other Windows) and run the build task under the gulpfile.
+The easiest way to get started is to open `src\umbraco.sln` in Visual Studio 2019 (version 16.3 or higher, [the community edition is free](https://www.visualstudio.com/thank-you-downloading-visual-studio/?sku=Community&rel=15) for you to use to contribute to Open Source projects). In Visual Studio, find the Task Runner Explorer (in the View menu under Other Windows) and run the build task under the gulpfile.
 
 Alternatively, you can run `build.ps1` from the Powershell command line, which will build both the backoffice (also known as "Belle") and the Umbraco core. You can then easily start debugging from Visual Studio, or if you need to debug Belle you can run `gulp dev` in `src\Umbraco.Web.UI.Client`. See [this page](BUILD.md) for more details.
 

.github/ISSUE_TEMPLATE/4_Support_question.md

@@ -1,9 +0,0 @@
----
-name: ⁉️ Support Question
-about: Having trouble with Umbraco? -> https://our.umbraco.com
----
-
-This issue tracker is NOT meant for support questions. If you have a question,
-please join us on the forum at https://our.umbraco.com.
-
-Thanks!

.github/ISSUE_TEMPLATE/5_Documentation_issue.md

@@ -1,9 +0,0 @@
----
-name: 📖 Documentation Issue
-about: See https://github.com/umbraco/UmbracoDocs/issues for documentation issues
----
-
-The Umbraco documentation has its own dedicated repository. Please open your
-documentation-related issue at https://github.com/umbraco/UmbracoDocs/issues
-
-Thanks!

.github/ISSUE_TEMPLATE/6_Security_issue.md

@@ -1,31 +0,0 @@
----
-name: 🔐 Security Issue
-about: Discovered a Security Issue in Umbraco?
----
-
-⚠️ PLEASE DON'T DISCLOSE SECURITY-RELATED ISSUES PUBLICLY, SEE BELOW.
-
-If you have found a security issue in Umbraco, please send the details to
-security@umbraco.com and don't disclose it publicly until we can provide a fix for
-it. If you wish, we'll credit you for finding verified issues, when we release
-the patched version.
-
-❗ Please read more about how to report security issues on https://umbraco.com/security
-
-A note on "Self XSS"
---------------------
-
-Umbraco is a CMS, that allows users to edit content on a website. As such,
-all _authenticated users_ can:
-
- - Edit content, and (depending on the field types) insert HTML and CSS in that
-   content, with a variety of allowed attributes.
- - Depending on the user level: Edit template files, and insert C#, HTML, CSS and
-   javascript in so on.
- - Upload files to the site, which will become publicly available.
-
-We see these functionalities as _features_, and not as security issues. Please
-report the mentioned items only if they can be performed by non-authorized
-users, or other exploitable vulnerabilities.
-
-Thanks!

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,11 @@
+blank_issues_enabled: true
+contact_links:
+    - name: ⁉️ Support Question
+      url: https://our.umbraco.com
+      about: This issue tracker is NOT meant for support questions. If you have a question, please join us on the forum.
+    - name: 📖 Documentation Issue
+      url: https://github.com/umbraco/UmbracoDocs/issues
+      about: Documentation issues should be reported on the Umbraco documentation repository.
+    - name: 🔐 Security Issue
+      url: https://umbraco.com/about-us/trust-center/security-and-umbraco/how-to-report-a-vulnerability-in-umbraco/
+      about: Discovered a Security Issue in Umbraco?

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,61 @@
+name: "Code scanning - action"
+
+on:
+  push:
+    branches: [v8/contrib,v8/dev,v8/bug,v8/feature]
+  pull_request:
+    # The branches below must be a subset of the branches above
+  schedule:
+    - cron: '0 7 * * 2'
+
+jobs:
+  CodeQL-Build:
+
+    runs-on: windows-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        # We must fetch at least the immediate parents so that if this is
+        # a pull request then we can checkout the head.
+        fetch-depth: 2
+
+    # If this run was triggered by a pull request event, then checkout
+    # the head of the pull request instead of the merge commit.
+    - run: git checkout HEAD^2
+      if: ${{ github.event_name == 'pull_request' }}
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      # Override language selection by uncommenting this and choosing your languages
+      # with:
+      #   languages: go, javascript, csharp, python, cpp, java
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+    
+    - name: configure Pagefile
+      uses: al-cheb/configure-pagefile-action@v1.2
+      with:
+          minimum-size: 8GB
+          maximum-size: 32GB
+          
+    - run: |
+        echo "Run Umbraco-CMS build"
+        pwsh -command .\build\build.ps1
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1
+      with:
+        config-file: ./.github/codeql-config.yml
+
+

.github/workflows/codeql-config.yml

@@ -0,0 +1,13 @@
+name: "CodeQL config"
+on:
+  push:
+    branches: [v8/contrib,v8/dev]
+paths-ignore: 
+  - node_modules
+  - Umbraco.TestData
+  - Umbraco.Tests
+  - Umbraco.Tests.AcceptanceTest
+  - Umbraco.Tests.Benchmarks
+  - bin
+paths:
+  - src