Replace dummy of message_widget with real instance.

This is done because message_widget was needed to show messages in the editor. A logbook dummy is created in order for message_widget to work.
Implement quicksave and autosave for editor; fix #1935
Modify save_map to return whether it was succesful
Modify editor quicksave and autosave to handle failure
Merge pull request #2033 from ThePawnBreak/editor-mapsave

Editor mapsave #1935