Feature/find+python+module

(From previous commit:)
    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.