We basically want to replace the way in which the open, save
and save as menu items work. By default, these 3 menu items call
OpenScene, SaveScene and SaveSceneAs respectively.
We can create three mel procedures to replace the way in which
the default functions work (in our case, we will only be adding
Once we have defined our mel procedures, we can use the menuItem
command to edit the existing menu items "openProject",
"saveItem" and "saveAsItem".