Wdb wrapper

Hi Bryan,

This time I added:
 * Pipe primitive wrapper;
 * WDB.delete();
 * copy() method to all primitive wrappers;
 * more testing, and required fixes when the tests failed initially; 

There's lots of primitives not yet covered, however they can still be accessed/created directly via the ctypes API if needed. For my modelling purposes the ones covered are sufficient - consequently adding the rest is not my highest priority right now. I would like to have other people also test what is already there and prioritize work based on real needs ! I consider the API not stable yet and it would be nice to have other people opinion on how it should finally look like.

Can you please confirm if the test cases work for you ? If so, and the pip install is also still working, I would like to push for a new release and ask for (alpha) testers !

Cheers,
Csaba