[mythtv] adding gnome-power-manager/HAL support to mythtv

[Ma Begaj]

> > It is not very useful to stop gnome-screensaver always when
> > mythfrontend is running. It should stop g-p-m/screensaver only if an
> > user is doing something (watching tv, listening to music, playing
> > games, watching videos ...).
>
> the logic is there already, it just needs to call also
> gnome-screensaver, not just xscreensaver.

Sounds good. Thanks

M.