use find_library instead of hardcoded path for COreServices on MacOS

This is required for successful use with bundling tools like pyinstaller.
Small fix in PyPy check - getattr raises exceptions on missing
attributes.
Merge pull request #80 from Tinche/pypy-fix

Small fix in PyPy check - getattr raises exceptions on missing
Adds bitdeli
Merge branch 'master' of github.com:celery/billiard
Bumps version to 3.3.0.7 and updates CHANGES.txt
flakes
Also set multiprocessing.current_process
Bumps version to 3.3.0.8 and updates CHANGES.txt
Fixes typo
Merge branch 'master' into 3.3