Code review comment for lp://staging/~gaspa/a4/mode_switch

Looks like this code just partially address the issue.
Although region is preserved in the drawing_area, arrows doesn't cycle correctly. For example: if you open a presentation, reach the third region, switch to editor, and hit the 'next' button, A4 will bump to the first region. Saving and restoring self.player.view_status similarly to self.player.current_region fixes everything.
Anyway, I am pushing the merge proposal with this fix, just to avoid waiting more time to have this branch re-submitted and re-reviewed (many of us are still in vacation, etc.). Since this is a trivial patch, we can easily rollback and/or re-factor the code if needed.

BTW: since current_region is a property, I'm wondering if we shouldn't rather use its getter and setter (and maybe re-factor view_status as a property as well).