Keep "lock-on-sleep" in sync with other components via XfceScreensaver
This requires an instance of XfceScreensaver to be around to work, but xfce4-power-manager has at least one linked to its lifetime in XfpmManager, and xfce4-power-manager is a prerequisite for xfce4-power-manager-settings.
Fixes: #71 (closed)
Related: libxfce4ui!98 (merged)