Added modules for finding Python libraries.

FindPythonModule.cmake offers the find_python_module() function,
which acts similarly to the simple invocation form of
find_package().

FindPythonCython and FindPythonNose are two specific cmake
scripts that use FindPythonModule to check for the presence
of their respetive packages.
Merge branch 'feature/find+python+module' of github.com:halfflat/CMake into feature/find+python+module

Conflicts:
	FindPythonModule.cmake