I hope this is right to make a pull request

made the save as a bit more bullet proof..
As we had problems that files could not be saved that way...

Then we have a general schema with extensions as a key {ext}.
This way it can happen that the app gets an mp4 instead of a maya scene file out of the library.
The extension setting would prevent that.
And if it is empty it wont filter anything

I thought it might be easier for you to examine what we want instead of having discussions via email...
And you can reject what does not make sense easily...

Enjoy Siggraph

Johannes