Reorganized files in hg-purge repo to push them into Mercurial.
README -> hgext/purge/README
purge.py -> hgext/purge/__init__.py
removed COPYING.GPL and .hgignore (already in the Mercurial repo)
Some functions were called as globals (i.e. I forgot some "self.")
Changset
de893ad6bd17 wrongly reversed the meaning of --nothing