Make PageVirtualPathAttribute value based on namespace instead of folder path.
Namespaces are more versatile in three ways:
* They obviously can mirror folder path since by default each folder is a "namespace provider"
* Some folders might not have "namespace provider" attribute giving more space to maneuver
* A separate project with precompiled views can have a different namespace (a sub-namespace that is) from the main MVC project. This way, for instance, project Areas could be moved into separate assembly allowing for better structuring of a project (combined with issue #110)
Namespaces are more versatile in three ways:
* They obviously can mirror folder path since by default each folder is a "namespace provider"
* Some folders might not have "namespace provider" attribute giving more space to maneuver
* A separate project with precompiled views can have a different namespace (a sub-namespace that is) from the main MVC project. This way, for instance, project Areas could be moved into separate assembly allowing for better structuring of a project (combined with issue #110)