Fix various problems with the widget relayout procedure
Two bug fixes.
Bug 1
Sometimes, after a resolution change or logout-login cycle, the widgets can get moved around in odd ways. The exact way to trigger this, I'm not sure, but the problems ceased to occur after removing a heuristic layout function call (polish()). I'm not exactly sure what the function was supposed to do or where it was even defined (I looked!), but removing it entirely seemed to have made everything behave itself better.
Bug 2
If the user intentionally changed their screen resolution to a size that they had not previously set their screen to, the widgets would be laid out in a new pattern so as to be approximately where they were supposed to be. However, the widget positions would not be saved after this happened, so if the user then proceeded to log out and log back in, the widgets would end up in strange places (I think probably from KDE loading the widget positions for a different resolution and trying to put them there). To solve this, the code now saves the widget layout immediately after repositioning the widgets after a resolution change. This makes the widgets stay where they are supposed to be after logging out and logging back in.