prevent window from growing when config is saved.

Use the content geometry (width() and height()) instead of the frame geometry
(frameGeometry().width()/height()) to save the width of the top level window
since this is what is set by the resize function.  Use the frame position (x()
and y()) for saving position which is what move() sets.
Merge pull request #612 from acornacorn/groovy-devel

Merging pull request to save window size correctly.

The result is still not perfect on my window manager (Unity) but it is a big improvement anyway, so merging.