Point to the binary distribution of Python.
Merge remote-tracking branch 'upstream/master'
Ensure only SSE2 instructions are used.

Cura is supposed to work on at least 32bit CPU on 10.6
Such CPUs support only SSE2.
Require power 1.2
Merge remote-tracking branch 'upstream/master'
Use --build-bottle to avoid processor specific flags.
Merge pull request #374 from GreatFruitOmsk/master

Fix crashes on Mac OS X 10.6 and CPUs without SSE4