Export MORSE scene as Python Builder script

This add-on is accessible from the File>Export>Save MORSE scene(.py) menu.

This option will only be available for MORSE scenes, that is, only if the script finds the Scene_Script_Holder object in the scene.

When invoked, it will generate a file with the same name as the .blend file, but will change the extension to .py. This file will be placed in the same directory from which MORSE was started.