Fix #620, Remove legacy / non-unobtrusive client side validation
- remove `ViewContext.UnobtrusiveJavaScriptEnabled` property and all references
- avoid `ViewContext.GetFormContextForClientValidation()` calls since
  ternary expression is more explicit and we were inconsistent
- improve `ValidationMessage()` comments
- don't treat `ModelState.IsValid` as if it were still nullable
Cleanup unused `FormContext` members due to legacy validation removal
- provide new property back for customer use
- remove unused FieldValidationMetadataClass
1. Introducing XML Input Formatters.
2. Adding DelegatingStream class
3. Unit + Functional tests for formatters.
Add friendly name to action descriptor. Issue 820

Used in error messages for various attribute routing pieces, and anywhere
that you need a display name for an AD.
Add friendly name to action descriptor. Issue 820

Used in error messages for various attribute routing pieces, and anywhere
that you need a display name for an AD.
Adding parameter replacement
Reacting to Roslyn package changes
Adding support for content negotiation.
This change consists of :
1. Conneg based on request headers, supports the following 3 scenarios:
	a. ContentType property on ObjectResult set to null or is empty.
	b. ContentType property on ObjectResult set to a single content type.
	c. ContentType property on ObjectResult set to multiple content types.

2. Parsing Helpers, comparers and extensions for comparing various http headers.
3. Tests.

Open workitems:
1. Remodel JsonResult and ContentResult to be a derivation of ObjectResult.
2. Populate DeclaredType.

Conflicts:
	src/Microsoft.AspNet.Mvc.Core/Formatters/OutputFormatterDescriptor.cs
	src/Microsoft.AspNet.Mvc.Core/Microsoft.AspNet.Mvc.Core.kproj
	src/Microsoft.AspNet.Mvc.Core/OptionDescriptors/OutputFormatterDescriptorExtensions.cs
	src/Microsoft.AspNet.Mvc.Core/Properties/Resources.Designer.cs
	src/Microsoft.AspNet.Mvc.Core/Resources.resx
	src/Microsoft.AspNet.Mvc.HeaderValueAbstractions/MediaTypeHeaderValue.cs
	src/Microsoft.AspNet.Mvc.HeaderValueAbstractions/MediaTypeWithQualityHeaderValue.cs
	src/Microsoft.AspNet.Mvc/MvcOptionsSetup.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/OptionDescriptors/OutputFormatterDescriptorExtensionTest.cs
	test/Microsoft.AspNet.Mvc.HeaderValueAbstractions.Test/MediaTypeHeaderValueParsingTests.cs
	test/Microsoft.AspNet.Mvc.Test/MvcOptionSetupTest.cs
Moving to the latest pattern of Specifying formatters using options
Responding to comments
Updating System.Xml.ReaderWriter to 4.0.10.0
Removing a stale proj reference in .sln
Fix Stylecop failure
- long line
Improve `HtmlHelper` extension points
- address all of #659 and a bit of #874 (avoid `public virtual` methods in
  `HtmlHelper`)

- make `MetadataProvider` and `GetClientValidationRules()` `public` and
  therefore available to extension methods
- remove unused `GetValidationAttributes()` overload
- make remaining `GetValidationAttributes()` overload (and not
  `GetClientValidationRules()`) `virtual`, allowing derived classes to
  change the attributes without overriding all callers
- reverse `GetValidationAttributes()` and `GetClientValidationRules()`
  parameter order to match precedence
- add `GenerateName()` and `GenerateValidationSummary()` to make
  `protected virtual` method names consistent
- `Name()`, `ValidationSummary()` and `TextArea()` are no longer `virtual`
  because `protected virtual Generate*()` methods exist for all
Make longest `@Html.DisplayForModel()` overload an extension method
- consistent with @Html.EditorForModel()` overloads
Return a copy of the route values in functional tests.

This is a workaround for a Json.Net + CoreCLR issue.
Changing GetLibraryExport to GetAllExports
[Issue #730] Attribute Routing: Flesh out attributes - Part 1.

1. Added a new AttributeRouteInfo class to store all the information for
   actions that are attribute routed.

2. Added a new ReflectedAttributeRouteModel class to store all the information
   related to attribute routes in the ReflectedApplicationModel.

3. Refactored ReflectedControllerModel and ReflectedActionModel to use ReflectedAttributeRouteModel
   instead of just the attribute route template.

4. Refactored ReflectedActionDescriptorProvider to use AttributeRouteInfo and ReflectedAttributeRouteModel
   instead of just the route template.

5. Added a CombineReflectedAttributeRouteModel method in ReflectedAttributeRouteModel that handles
   combining two ReflectedAttributeRouteModel instances.

6. Removed the AttributeRouteTemplate class and moved the methods for combining attribute routes to the
   ReflectedAttributeRouteModel class.

7. Added unit tests for ReflectedActionModel and  ReflectedControllerModel that
   cover the usage of AttributeRouteInfo.

8. Added unit tests for CombineReflectedAttributeRouteModel.
[Issue #730] Attribute Routing: Flesh out attributes - Part 2

1. Unsealed the Http*Attributes so that they can be extended and customized.
2. Added the same constructors as HttpGet to the rest of the Http*Attributes.
3. Added unit tests to validate the implementations for the IActionHttpMethodProvider.
4. Added functional tests to cover extra attribute routing scenarios like a test for an
   action with an HttpDeleteAttribute on it and action with AcceptVerbsAttribute and an
   action with a custom HttpMergeAttribute implemented.
[Issue #733] Attribute Routing: Implement Order

1. Added an Order property to IRouteTemplateProvider, ReflectedAttributeRouteModel,
   AttributeRouteInfo, AttributeRouteLinkGenerationEntry and AttributeRouteMatchingEntry.

2. Changed the implementation of AttributeRoute to take the order into account when routing
   incomming requests and generating links.

3. Ensured a stable ordering of route entries with the same order and precedence for route
   matching and link generation based on the template text.

4. Added tests to validate that the precedence gets respected in route matching and link generation.

5. Added tests to validate that the order gets respected in route matching and link generation.

6. Added tests to validate that the order gets respected over the precedence for route matching
   and link generation.

7. Added tests to validate that routes with the same order and precedence expose a stable ordering
   for route matching and link generation.