Runs the given scent.py file.

def load_file(filename):
    "Runs the given scent.py file."
    mod_name = '.'.join(os.path.basename(filename).split('.')[:-1])
    mod_path = os.path.dirname(filename)

    if mod_name in sys.modules:
        del sys.modules[mod_name]
    if mod_path not in set(sys.modules.keys()):
        sys.path.insert(0, mod_path)
    return ScentModule(__import__(mod_name, g, g), filename)