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.
This is according to the last line in the [installation section](http://symfony.com/doc/current/bundles/SensioFrameworkExtraBundle/index.html#installation) of the symfony doc for the sensio bundle.

seems to make sense - but my huge wtf is why the functional test for `@Tag` works without this line. the `@InvalidationRoute|Path` do not work without the line.