support for hierarchical module naming schemes

@geimer: this should fix the problem that's blocking you right now

I might need to figure out one more thing w.r.t. the devel module name before this really works for you, I'm looking into that...
unfortunately, these errors also occur in common typos in dict usage or function names. this is a way top wide catch-all. i'm not in favour of creating custom error classes, but these specific cases should be dealt with with less generic errors.