n-th bug fixing patch from Vincent:

n-th bug fixing patch from Vincent:

Almost all methods in the GuiPainter class have something like

if (!isDrawingEnabled())
  return;

except GuiPainter::fillRectangle(...) !!

Adding this will solve

gmane.editors.lyx.devel/109857
gmane.editors.lyx.devel/109859
http://bugzilla.lyx.org/show_bug.cgi?id=4937
http://bugzilla.lyx.org/show_bug.cgi?id=5027
http://bugzilla.lyx.org/show_bug.cgi?id=5235

Maybe also:
http://bugzilla.lyx.org/show_bug.cgi?id=5230

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@26351 a592a061-630c-0410-9148-cb99ea01b6c8