Minor script cleanup.

Fix inconsistencies in uncompyle2 script, rename to scripts/uncompyle2 & add to
setup.py (these are all changes from wibiti). Also, change script headers so
they work on Windows too. Remove build folder from repo & add .gitignore so it
doesn't inadvertently get added again.
Merge pull request #13 from ralph-moeritz/master

Minor script cleanup