Added FileSystemProviders config section

Added FileSystemProviderManager class for fetching a file system provider by alias (this should probably be moved into the Umbraco context in 4.10)

src/Umbraco.Core/Configuration/FileSystemProviderElement.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Linq;
+using System.Text;
+
+namespace Umbraco.Core.Configuration
+{
+    public class FileSystemProviderElement : ConfigurationElement
+    {
+        private const string ALIAS_KEY = "alias";
+        private const string TYPE_KEY = "type";
+        private const string PARAMETERS_KEY = "Parameters";
+
+        [ConfigurationProperty(ALIAS_KEY, IsKey = true, IsRequired = true)]
+        public string Alias
+        {
+            get
+            {
+                return ((string)(base[ALIAS_KEY]));
+            }
+        }
+
+        [ConfigurationProperty(TYPE_KEY, IsKey = false, IsRequired = true)]
+        public string Type
+        {
+            get
+            {
+                return ((string)(base[TYPE_KEY]));
+            }
+        }
+
+        [ConfigurationProperty(PARAMETERS_KEY, IsDefaultCollection = true, IsRequired = false)]
+        public KeyValueConfigurationCollection Parameters
+        {
+            get
+            {
+                return ((KeyValueConfigurationCollection)(base[PARAMETERS_KEY]));
+            }
+        }
+    }
+}

src/Umbraco.Core/Configuration/FileSystemProviderElementCollection.cs

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+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Linq;
+using System.Text;
+
+namespace Umbraco.Core.Configuration
+{
+    [ConfigurationCollection(typeof(FileSystemProviderElement), AddItemName = "Provider")]
+    public class FileSystemProviderElementCollection : ConfigurationElementCollection   
+    {
+        protected override ConfigurationElement CreateNewElement()
+        {
+            return new FileSystemProviderElement();
+        }
+
+        protected override object GetElementKey(ConfigurationElement element)
+        {
+            return ((FileSystemProviderElement)(element)).Alias;
+        }
+
+        new public FileSystemProviderElement this[string key]
+        {
+            get
+            {
+                return (FileSystemProviderElement)BaseGet(key);
+            }
+        }
+    }
+}

src/Umbraco.Core/Configuration/FileSystemProvidersSection.cs

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+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Linq;
+using System.Text;
+
+namespace Umbraco.Core.Configuration
+{
+    public class FileSystemProvidersSection : ConfigurationSection
+    {
+        private const string PROVIDERS_KEY = "providers";
+
+        [ConfigurationProperty("", IsDefaultCollection = true, IsRequired = true)]
+        public FileSystemProviderElementCollection Providers
+        {
+            get { return ((FileSystemProviderElementCollection)(base[""])); }
+        }
+    }
+}