JERSEY-2012: Add support for binding BV error messages to MVC views

- feel free to review but DO NOT APPROVE - missing documentation and tests
- first draft

- added @ErrorTemplate to display error pages
- BV support for @ErrorTemplate
- Mustache template processor (in separate extension module)
- link shortener example

Change-Id: I0515d62ecf0d9b737c4dce3eab082a2637332d07