[#2561] Updated libffi & Python sources.

Problem?
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Python's latest 2.7.x releases fix a number of security issues.

Solution?
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Update the Python sources. And while at it, update `libffi` sources as well. 
The patches for AIX/Solaris in `setup.py` were forwarded patched to the pristine 2.7.9 sources.

How to check?
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Test, test, test… :)

reviewer: @adiroiban