Added req.txt with 'pygame' entry
Added --allow-external option
Restore back just 'pygame' to see the error 1cemor
Added url to official python 1.9.1 release.
Change req.txt to MOCK, and write MOCK to conf.py
Merge branch 'req' into docs

Made truly working autodoc under readthedocs engine:
    1. Added 'mock' to req.txt (requirements for pip)
    2. Added mock cycle to conf.py to pull pygame source code