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...
why? `easyconfig/tools.py` isn't too big at all? or do we want to move every function into it's own module and have 100s of lines of imports everywhere? ;)