really a crappy dialog at the moment, not even a canvas button!).
Current features are;
* Multi-threaded printing so while printing the canvas is fully responsive.
* Do the actual painting code in the main-thread to avoid locking problems.
* Nice progress reporting using the KoProgressUpdater.

This multi-threaded printing is only really useful for multi-page documents,
I'll adjust KWord to use it and I'm sure that KoPageApp can inherit from
this one to implement printing there with ease.

svn path=/trunk/koffice/; revision=689686