[Lazarus] TGraphicControl changes

[zeljko]

Hi all,
I just changed behaviour of TGraphicControl.Update (overrided TControl.Update) 
in r31132 so it does not request paint over whole parent handle, but just 
invalidates clientrect of TGraphicControl.
If someone rely on TGraphicControl.Update and expect that it'll request paint 
over complete parent handle , than such code should be changed.
TGraphicControl.Update calls invalidateRect() only for TGraphicControl client 
rect.

zeljko