Cleanup invalidation annotation

To prepare for #117 i wrote some more functional tests. One big wtf though.

Also split the tag specific controller into a separate controller for better readability.

And make InvalidateRoute explicit about expression.
moving into a getter that instantiates if needed.

i validate the existence of expressionlanguage in the annoation class, so i think we never ever can have fatal errors anymore now, and can use everything without expressions properly.