VuMeter bar to use full widget size

Check widget size to know bar size instead of checking bitmap size to allow resizable VuMeters.
Also suddenly found fix for unavailable horizontal VuMeter peaks.
P.S. I don't know C++ at all, so code may be "incorrenct", but it works with all skins, just tested.
same as above -- sourceRect should remain as is and you should make a targetRect rect that is the section of the widget that needs painting.