JAL-3560 avoiding Graphics.setClip

JAL-3560 avoiding Graphics.setClip

Now that Graphics.setClip is supported, it is important to avoid it
whenever possible. It requires a full run back through the graphics
stack and return twice in order to clear the clip and reset it with all
other characteristics of the graphics state intact. This was
particularly notable in JViewport, creating very sluggish handling of
FeatureSettings, particularly in Firefox.