Update razor precompilation diagnostics:

consistently add razor errors to diagnostics.

This will start producing proper errors with line numbers when Roslyn updates the default diagnostics formatter.
Remove usings
Updating ModelBinding tests to work in Mono
[Fixes #1183] Response uses chunked encoding when returning a string
Updating Microsoft.AspNet.Mvc.Core.Test to work on Mono
Updating build.sh
Remove and sort usings and fixing formatting
Fixing build break
Removing Overloading
Fix for #975 - Implementing IActionConstraint and ActionMethodSelectorAttribute

IActionConstraint follows a provider model similar to filters. The
attributes that go on actions/controllers can be simple metadata markers,
the 'real' constraint is provided by a set of configurable providers. In
general the simplest thing to do is to be both an
IActionConstraintMetadata and IActionConstraint, and then the default
provider will take care of you.

IActionConstraint now has stages based on the Order property. Each group
of constraints with the same Order will run together on the set of
actions. This process is repeated for each value of Order until we run out
of actions or run out of constraints.

The IActionConstraint interface is beefier than the equivalent in legacy
MVC. This is to support cooperative coding between sets of constraints
that know about each other. See the changes in the sample, which implement
webapi-style overloading.
Versioning functional test.