Implemented: U4-2692 Add attribute access to property editor prevalues

src/Umbraco.Web.UI.Client/docs/src/tutorials/Validation.ngdoc

@@ -0,0 +1,9 @@
+@ngdoc overview
+@name Creating a property editor
+@description
+
+##Overview
+
+First, I'll explain the validation system in the manifest:
+The validation specified in the manifest is for server side only. Client side validation needs to be put into markup (I will write up a whole thing on the full validation process real soon!). Preferably a dev (and ourselves) will setup the same client side validation as the server side validation but the most important validation is server side so people cannot hack stuff.
+Each validation item in the validation array specifies a validation type that is executed against the posted value. What this means is that manifest based property editors will generally only be able to store 'simple' values, otherwise are auto-validation will not 

src/Umbraco.Web.UI.Client/src/views/propertyeditors/dropdown/dropdown.prevalue.html

@@ -1,5 +1,5 @@
 <div>
-    I will finish this tomorrow.
-    <!--<input type="text" ng-model="model.value" />-->
+    
+    <input type="text" ng-model="model.value" />
 </div>