Merges Alistar's changes and the base version

Merges alistar's changes.
(see: https://github.com/benjie/MythPyWii/blob/master/myth_py_wii.alister.py)

Also uses optparse instead of manually writing the parser.
Uses try/except around the system call

Use a try/except around the system call since xset doesn't seem critical
to the usage.

The script seemed to crash periodically before this.
There is probably a better way (fail to run if xset isn't available?)

Subprocess is better than os.system for calls.