RoslynCompilationService should set the generated code when compilation is successful

Fixes #895
Enabling basic input formatter selection.

Conflicts:
	Mvc.sln
	src/Microsoft.AspNet.Mvc.Core/Formatters/TempInputFormatterProvider.cs
	src/Microsoft.AspNet.Mvc.Core/Microsoft.AspNet.Mvc.Core.kproj
	src/Microsoft.AspNet.Mvc.Core/ReflectedActionInvoker.cs
	src/Microsoft.AspNet.Mvc.Core/ReflectedActionInvokerProvider.cs
	src/Microsoft.AspNet.Mvc/MvcServices.cs
	test/Microsoft.AspNet.Mvc.Core.Test/Microsoft.AspNet.Mvc.Core.Test.kproj
	test/Microsoft.AspNet.Mvc.Core.Test/ReflectedActionInvokerTest.cs

Conflicts:
	src/Microsoft.AspNet.Mvc.Core/Formatters/TempInputFormatterProvider.cs
[Fixes #1035] RouteGroupConstraint should only be added once for non attribute routed actions

1. Changed ReflectedActionDescriptorProvider to add RouteGroupConstraint only once
   for non attribute routed actions.

2. Added tests to cover the scenario.
Clean up `AssociatedMetadataProviderTest`
- remove unused nested class `ModelWithReadOnlyProperty`
- remove unecessary nested classes `RangeAttribute` and `RequiredAttribute`
- use `Assert.NotEmpty()` and `Assert.Single()` where appropriate
Reacting to System.IO package version change
Add `ModelMetadata.HasNonDefaultEditFormat` property
- add `DataType` property to `CachedDataAnnotationsMetadataAttributes` in support of `ComputeHasNonDefaultEditFormat()`
- provide doc comments and flesh out the implementation of `DisplayFormatString` and `EditFormatString`

nits:
- add comment about _not_ overriding `ComputeIsComplexType()` in `CachedDataAnnotationsModelMetadata`
- restore alphabetic order in `CachedDataAnnotationsMetadataAttributes`
- seal `SimpleDisplayText` in `CachedModelMetadata<TPrototypeCache>`, matching MVC 5.2
Move two recently-added `[HiddenInput]` tests into `CachedDataAnnotationsModelMetadataProviderTest`
Test `DisplayFormatString`, `EditFormatString`, and `HasNonDefaultEditFormat`
- `DisplayFormatString` and `EditFormatString` now based on attributes
- `HasNonDefaultEditFormat` is new
- confirm `DataType` and `ScaffoldColumn` in `CachedDataAnnotationsMetadataAttributes`
Address TODO item with new `HasNonDefaultEditFormat`
- avoid overriding a datetime format if format was already customized
- primarily affects the default Date and Time editor templates because they
  are often used due to `[DataType]` attributes with "default" edit formats
Back `HtmlHelper.Html5DateRenderingMode` with new `ViewContext` property
- provides expected scoped semantics
- helps a bit with #448 but does not provide an app-wide default
Test data/time templates
- focus on affect of `ModelMetadata.HasNonDefaultEditFormat` and
  `IHtmlHelper.Html5DateRenderingMode`
- work through `TemplateRenderer` because individual templates only do
  formatting in a few cases
Changes to introduce CanWriteResult for Xml OutputFormatters.