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...
another function that is getting less and less to do with easyblocks. this should be nothing more then
```
modtool.load([self.mod_name],mod_paths,purge)
```