fdo#73487: Better pixelization of lines for on-screen rendering.

Conflicts:
	drawinglayer/source/processor2d/vclpixelprocessor2d.cxx
	drawinglayer/source/processor2d/vclpixelprocessor2d.hxx

Change-Id: I95d087a1f4841bfb7f665bcfebecd4c22c817958