gui: Give QMenus correct parents and descriptive names for recorded scripts.
Deleted print statement.
LayerViewerGui: Removed 'View' menu code, which now resides in volumina.VolumeEditorWidget
shell: moved 'debug' and 'help' menus to the end of the menu bar (after applet menus such as 'view')
PixelClassification: Don't allow the user to paint labels during 'save and predict'