Enable specification of external assemblies for controller discovery on ServiceStack.Mvc.FunqControllerFactory.  Unit tests added to preserve default behaviour in:

tests\ServiceStack.Mvc.Tests\
tests\ServiceStack.Mvc.Stubs.Tests\
Move ServiceStack.Mvc.Stubs.Tests to external lib test assembly
Remove ServiceStack.Mvc.Stubs.Tests project from ServiceStack.sln
Merge pull request #600 from chappoo/master

Enable specification of external assemblies for controller discovery …