Match the rostype string with python module target name

[asmodehn]

where possible...

This would allow us to connect nicely with genpy.message._get_message_or_service_class since it is attempting to import the package to retrieve the message class...

This might be tricky/impossible with relative or deeply nested messages though...

[asmodehn]

Doing this might prevent allowing custom import targets or nested messages, so maybe we could decide it is up to the caller to translate the name properly when calling genpy.message._get_message_or_service_class ?

[asmodehn]

OR we could reimplement this feature in rosimport... with a similar API.

[asmodehn]

Actually the only problem seems to be when we are trying to use this API with "private messages" (message that are not at the root or the ros package).
It seems sensible to not support this case, and instead use the python module way in that case...