Fixed a small problem with the fife timer library. There was a problem with UH when clicking on certain buttons on the main menu which cased a hang/crash. The timer now stops itself before executing the callback.

# -*- coding: utf-8 -*-

__all__ = [
	'basicapplication',
	'fife_compat',
	'fife_timer',
	'fife_utils',
	'fifelog',
	'filebrowser',
	'pythonize',
	'savers',
	'soundmanager',
	'fife_math'
]