Graphos: text alignment and other fixes

I finally fixed text alignment in Graphos! It was broken since a long time, perhaps since Graphos 0.1, probably due to the conversion made from GDraw. You had the controls in the editor, but then it didn't draw correctly!

Another long-standing bug was the manipulation of handles of a closed bezier path: the handles inside the path could not be touched. I think this bug existed even in GDraw!


A lot of work then went into restructuring the whole architecture that handles the zooming of the view. previously, everything was recomputed, there was no notion of original size, everything was transformed back and forth on the fly. While quick and easy, this provided serious problems when saving! Furthermore it means that there is data corruption when performing zooms!

Now, the original information is stored inside each object and everything is then calculated for representation. Some zoomed data is pre-calculated, other not. Probably there can be quite some optimization, but first everything needs to be debugged, since this is a quite consistent change. No new format is necessary since previosuly saving with a zooom different from 100% resulted in a broken file anyway.