[GSoC] Cleanup internal drawing units in Calc

Hi all!

Work has been difficult on this project, I got a bit stuck.
ScOutputData::DrawRotatedBorder() turned out to be trickier than I thought;
when I try changing the points of the polygon to be drawn, it has no effect
on what is actually being drawn, and a Processor is used for drawing which
also doesn't help seeing things clearer. (I read up on Processors and it
didn't really help so far.)

Also this week I'm doing a presentation about my thesis project, and
preparation for that and travelling took up a lot of my time.

Hopefully I'll be able to get through this roadblock soon.

All the best,
Krisztian