When screen dimensions are shrinked, panel will be moved at the correct location but will not be resized correctly. Also,
when screen dimensions are changed again, increasing sizes, panel would not catch that. Here, 'the hack' is to track
root window dimension changes and react on that, since relaying on _NET_WORKAREA is not always good; struts dimentions affects workarea size.
Main menu now has tooltips, which is Comment value from .desktop files. Also, since XdgMenuReader directly plays with MenuItem,
MenuItem::init_extensions() is used to reset uncommon values.
