use namespace from traits

This adds support for Annotated Methods in Traits and is a follow up and replacement for PR #20

Annotations inside of Traits can use different Namespace than the including Class, see ClassUsesTrait.php in this PR for example.
As Methods of Traits can be overwritten, the Namespace of the actual class needs to be used.

Known Issue:
In the rare case of having the Trait and the Class defined in the same File *and* a method from Trait is overwritten in the Class *and* the namespace of an annotation differs than the namespace from the trait is used instead of the correct one from the class.