Support optional route constraints in MVC

This PR
1. Adds tests for inline constraint
2. Fixes tests broken by Routing change for inline constraints

would recommend to install https://visualstudiogallery.msdn.microsoft.com/da227a0b-0e31-4a11-8f6b-3a149cf2e459 to help you see that while you are coding.
this works for dev 14 as well.