definition type shouldn't return import, we'd rather want the implementation name -> #340
implement a Completion.type version for #340, follow imports if they are in a from clause or if its a longer imnport
more type tests
make param backwards compatibility clearer
add a Documentation() class to the API, which will be used in the future for all kind of docstrings. Also add a documentation method on BaseDefinition that returns a Documentation object. Deprecate at the same time its doc and raw_doc functions