A sad day in the U.S of A.
First public release. Add trepan3k debugger command functions
mathics3: Go into a Mathic3 shellmbacktrace: backtrace showing interesting Mathics3 frame interpretationmup: frame up allowing for jumping to interesting Mathics3 framemdown, frame down allowing for jumping to interesting Mathics3 frameprintelement: print customized for Mathics3 objects