Comment 6 for bug 1290737

Same as in #4, but using a more pythonic way.

2 remarks:
1) One could easily sync the 'Lock screen when going for suspend/hibernate' setting of xfpm with the enable/disable light-locker setting (or even the lock screen setting in the session settings). However this would be a one way sync, since disabling it in xfpm would not disable light-locker.
2) Xfpm seems to have a very weird bug in that way, that changes made via xfconf are applied, but not reflected by the xfpm ui, unless one had used the ui to changes those settings before. E.g. if one never used the sliders to change dpms timings and one changes the timings via xfconf, xfpm applies the changes but does not adapt its ui to the changes.