Feature request: View->Show Unresolved References

[stefanottili]

0.30.4 implement the very useful #2110

Currently the display of unresolved references is tied to View->Show Cell Frames.
It would be very useful to have a separate View->Show Unresolved References.

And since I'm using these and View-Show Text all the time, it would be nice if these menu items also could be default Buttons.