Codeplex-1319 - Disallow {controller} and {action} in attribute routes

This change prevents the use of {controller} in all attribute routes, and
the use of {action} in attribute routes on action methods. This validation
is in place to prevent scenarios where a user takes a working traditional
route and copy-pastes it into attributes.

Use of these route parameters in the scenarios where it's now prohibited
is very very likely to be a mistake and won't do anything useful. For any
valid scenarios that are blocked by this, the workaround is to use a
different parameter name.