This option allow Blender to be linked against the Framework python
It's useful if you want to have blenderplayer and bpy in the same application and need to avoid PyThread problems.
patch reviewed by Jens Verwiebe before 2.66. He may want to change something though.
(also small: I changed:
/Library/Frameworks/Python.framework/Versions//python
by
/Library/Frameworks/Python.framework/Versions//Python
as the latter seems to be the norm)