Revert "1197 Support [ResponseType(typeof(void))] for actions that return an IHttpActionResult with no response content"

This reverts commit 532db0188d35e92d47581839ee814680fddb2feb.
Revert "Revert "1197 Support [ResponseType(typeof(void))] for actions that return an IHttpActionResult with no response content""

This reverts commit 52a73b6ba584f6b573acfe1a73ab4533a8ccc6a6.
Update Versions from 5.0 & 3.0 to 5.1 & 3.1
Fix CodePlex 744

Return the display name in an error message if set.
Fix CodePlex 744

Return the display name in an error message if set.
Downgrade razor version back to 3.0
HttpRequestContext cleanup.
Fix HttpRoutingDispatcher locating route data (fixes #1290).
896 Set the appropriate BOM type for Help Page .cshtml files.
Fixing the help page build task to output .pp files using UTF8 encoding with BOM (which is what VS does by default).
Part of this bug is actually caused by a known issue in NuGet (see the link below) and will be addressed by the NuGet team.
http://nuget.codeplex.com/workitem/3174
Update Microsoft.Owin version to latest build
Preserve stack trace for ApiController exceptions (fixes #1313).
Issue 797: default odata routing conventions is missing support for url's
generated by WCF DS client

1) mapping POST ~/Customers(42)/Orders to PostToOrders.

2) mapping POST ~/Customers(42)/Ns.SpecialCustomer/SpecialOrders to
PostToSpecialOrdersFromSpecialCustomer

3) mapping PUT/POST to
~/Customers(42)/Ns.SpecialCustomer/$links/SpecialOrders to
CreateLinkToSpecialOrdersFromSpecialCustomer

4) Also, changing links routing convention to route to
CreateLinkTo{navProperty} if that method is declared instead of just
CreateLink.
Fix codeplex bug 1312

System.Web.Razor.TextChange creates a wrong Old Text property

The GetText method was using a property instead of the passed parameter, also added an optimization for the common case of typing a single char (OldText length is always zero)
Fix ExceptionResult status code (fixes bug # 1318).
Issue 614: Enable FxCop for System.Net.Http.Formatting.NetCore
Make external component dependencies stable.
Fix FxCop errors when running CodeAnalysis on Debug builds.

- Remove unused locals in OData
- Remove redundant casting in EdmLibHelpers
- Add Suppression for Thread.Current Principal for unused local
- Use CultureInfo.InvariantCulture when writing out tracing for razor editor traces elapsed time values.
Better error message when can't construct model for Action
https://aspnetwebstack.codeplex.com/workitem/892
- MissingMethodException often provides a less-than-helpful message; problem here centers on Activator.CreateInstance()
- To avoid compatiblity problems, throw same type of Exception, preserve original Message and stacktrace.
- Fix all instances of the problem in System.Web.Mvc.dll and Microsoft.Web.Mvc.dll
- Activiator.CreateInstance() is called elsewhere in these assemblies but not for types than may lack a parameterless constructor
- Add or update tests covering affected methods

nit: Let VS reorder the System.Web.Mvc.csproj file
Address review comment against Commit a20dd5738e8f
- Lowercase "type" in new exception's Message
791: Support nested property on complex type in $orderby