Visualize skeleton
Add a toolbar to mainwindow as global toolbar.
Remove file buttons from toolbox.
Cleanup code
Cleanup code and rename update_undo_redo to update_tools
Remove handlebox widget and tweak the toolbox layout.
Remove border of tool button of toolbox
Use smal icon size (16x16) for toolbar buttons
Add menu item names
Fine-tune UI layout of defalut widgets on toolbox
Merge branch 'toolbar' of github.com:jcome/synfig into toolbar