Prompts

NEW CHANGES
- Prompts user to save if user hasn't saved already [Umer]
- Added some images [Umer]
- Added EDIT menu with a reset menu item, as well as zoom in and zoom
out [Umer]
- Prompts now appear when selecting 'open' as well as when opening
recent files
- Prompts now appear differently for changes as well as just file saving