Apply VS' FormatDocument and RemoveAndSort to all *.cs files
- #EngineeringDay
- VS does not yet format auto-properties nicely; reverted what it did

Also revert changes under
- test/Microsoft.AspNet.Mvc.Razor.Host.Test/TestFiles
Add missing license headers
- #EngineeringDay
- license present but incorrect in just a few files
- skip generated files such as Resources.Designer.cs and files under
  test\Microsoft.AspNet.Mvc.Razor.Host.Test\TestFiles\Output
Replacing Assert.Equal(null, Assert.Equal(true \ false etc with
appropriate Xunit equivalents
Fixing build break
Simplifying InlineConstraints tests

Right now these use a commandline adapter to inject some data into the
tests, but it's really not needed. Instead, these routes use a prefix to
ensure that the scenario under test is isolated.
Avoid NREs in MVC sample
- see e.g. results of `GET ~/Home/Post`
- use parentheses to avoid `?` confusing Razor

nit: remove unused Home/Test.cshtml view
Extend MVC Sample functional test to include all Home views
Touch up tag helper sample
- provide list of users on Index page
 - currently uses only the `<a/>` helper but left `<label/>` and `<input/>` comments
- get date picker working on Create and Edit pages
 - add `[DataType]` annotation
 - use format browsers recognize

nits:
- move "Create New" link to the bottom of `~/Home/Index`
- correct code comment about assigning to a `ViewBag` property
React to aspnet/Razor#210 changes.

- Added the ErrorSink pass through values for our overridden classes.
Switch to new AddXXX methods which use TryAdd
Switch to AddMVC
Change AddMvc to use TryAdd as well