- added a button to clear de GUI preferences in Preferences -> General -> Gui Settings -> Clear GUI Settings
- added key shortcuts for the shape transformations within Geometry Editor: X, Y keys for Flip(mirror), SHIFT+X, SHIFT+Y combo keys for Skew and ALT+X, ALT+Y combo keys for Offset
- adjusted the plotcanvas.zomm_fit() function so the objects are better fit into view (with a border around)