Created Statusbar widget.
- Moved code from SPDesktopWidget to UI::Widget::Statusbar.
- Use .ui file to fill Statusbar.
- Added new actions for setting zoom and rotation to arbitrary values.
- Converted Statusbar Zoom and Rotate popovers to Gio::Menus.
- Merged the two SPDesktopWidget constructors (only one was used and it immediately called the other).
Edited by Tavmjong Bah