Add Insert Separator to Shelf Editor
In Maya 2017, there are new "separator" items in the default shelves (Curves / Surfaces, Polygons, Sculpting, Rigging, etc.). Turns out, in the MEL files of the shelves, the snippet of code is quite small. However - this is quite annoying to edit the MEL file for the shelf in order to get separators to appear.
It would be ideal to create a new button in the Shelf Editor, next to "New Item", and call it "New Separator".
Icing on the cake would be to then reveal the parameters that the separator contains: