problems with one-button mouse on Macintosh
The one-button mouse on the Mac makes it impossible to do certain actions
required by the Kepler graph editor (e.g. activating popups for controls)
especially since <Cntr>xx functions are used by Kepler. The key handlers should
be rewritten to map to <command> keys on the mac so that <cntrl>click works with
Note that the <del> key on the Mac will not delete controls.
Mac problems can be avoided by use of an external 2-button USD mouse.