Have MakeProgramZip.py use os.walk
Resources: Only read wad lumps when asked

* We now leave wad directory entries empty until we're asked for them
specifically, then cache them when reading them the first time.
* Added some logging facilities.
Create a pydoom package and move scripts there
Resource fixes

* Need an absolute path for pydoom.utility
* Typo prevented from resetting global namespace upon F_END/S_END