drawn in page.

PagePainter:
  Added 2 convenience function to change the alpha component of an image
  and do it while colorizing the image in a single pass.
  QPainter->drawPixmap unbuffered render for AText marks, AStamp pictures
  and AGeom of type InscribedSquare.

Can't wait for Arthur's painter to do the full range of painting effects
with a very simple interface, faster than my dirty implementation and
over all: not crashing! (mine does! :-)

svn path=/branches/kpdf_annotations/kdegraphics/kpdf/; revision=404088