[CMake] Choose Python version on OS X

[Enrico Franchi]

I've got Python 2.6 installed with MacPorts (MacOS X 10.5),
thus the framework is in /opt/local/Library/Frameworks.

CMake always finds system Python (FIND_PACKAGE(PythonLibs)).

I have already tried hacking CMakeFindFrameworks in order to add /opt/ 
local/Library/Framework to
the searched paths. However, at the end PYTHON_INCLUDE_PATH is always
/System/Library/Frameworks/Python.framework/Headers

What is the best way to have my own Python version detected?

What is the rule cmake uses to choose the Python installation to use?

Thanks in advance,
	enrico