Renamed package pyobdlib to obd

I've renamed pyobdlib to obd, since IMO, the rest (py and lib) is redundant.

Also:
- removed some dead code
- replaced the custom debug utilities with Python logger

I'm planning to do some more *aggressive changes*, like removing pyobd (the wxPython part), since:
1. it's broken,
2. according to the documentation in the original project, it doesn't work with recent versions of the library, and
3. the code is a mess.

I think a proper client could be implemented as a separate project (*do one thing and do it well*) and the code could be rescued.

If that's not the way you were envisioning your project to evolve or are just not interested, please let me know and I'll keep working on my repo :)