Fix load of python module PIL egg.

there are 2 problem to prevent the egg be loaded.

1. on darwin/win32, only pyo can be loaded by xbmc, pyc can not, but the egg was built to pyc without py source, so add the souce to egg fixes this.
2. the egg file is not in python's sys.path, so no one can load it without add the egg file into sys.path, fix it by add a PIL.pth file in the site-packages dir which include the egg filename.