TODO:

Before 2.16.0

 * Implement the low power changed signal
 * Don't show "ac disconnect" when removing power cord while suspended then resumed.
 * Throw dbus errors when we fail dbus methods: org.gnome.PowerManager.NotInhibited.

After 2.16.0

 * Make strings more translatable
 * Integrate g-p-m with more modules, e.g. nautilus.
 * Add the cpu frequency support when it gets added to HAL
 * Put the graphing stuff out of process
 * Control more stuff for UPS's (NUT stuff?)
 * "don't notify me of this anymore" on the libnotify thing.
 * Give the user the ability to force an Inhibit()'d action
 * Use the callbacks in libnotify to do a What's this? type help prompt.
 * Give user a choice to abort all actions.
