Ensure default values are included in explicit routes

Address the issue identified in
http://stackoverflow.com/q/15650973/246811 where routes would not be
matched when default values of primitive types were used.

Added a unit test to reflect the expected behaviour.
Added default excludeDefaults = false
Response should be 204 No Content for void methods by default.  Use endpoint configuration settings.
Fix broken razor tests
added regression test to be sure that ValidationFeature can be called twice without problem