Limit the maximum number of Model errors to a reasonable value.

Fixes #490
Updating release NuGet.config
Updating dev NuGet.config
Changes to show intellisense for @inject directive
Merge branch 'release' into dev
Fix for codeplex-1120 - Move CreateSerializer out of the base class

This is a small refactor as a precursor for api-explorer work.
Porting razorpage perf improvements from codeplex-2119

These changes were worth 2-3% of execution time on a page that makes heavy
use of attribute writing.

Making the overloads for writing a string public should show a small
throughput increase for a typical razor page.
cr feedback
Removing XmlSerializerInputFormatter from the list of Formatters.
Introducing a functional test for XmlSerializerInputFormatter.