Infinite canvas issues

[LukasT.dev@gmail.com]

This patch [1] fixes the rulers. I'm sending it as I don't want to break svn 
master and I'm expecting my hard drive to die soon.

If you use git, it should be easy to apply patches by

git apply ~/../koffice/000*-patch-name

[1] http://lukast.mediablog.sk/patches/0006-Fix-for-the-rulers.patch

I mistakely commited to my branch one paintop called experimental, so just 
comment it in CMakeLists.txt in paintops dir. 

boud suggested to commit to svn. So if you found issues, let me know so that I 
will fix them before commit to svn.

This patches are so far just for QPainter canvas. OpenGL canvas should be 
easier.