jobctrl: use shell for subprocess if trying without it fails

ipy_leo: implement %lee hist (open input + output history)

ipy_leo: rename %leo to %lee, make it more useful (edit macros and other objects)

ipy_leo: @ev node support, have _p (LeoNode for current pos) in user_ns on normal ipython script execution

Lots of cleanup and update_commander - requires cvs leo to work

%mb completer now only completes on the first argument (and uses file name completer for the rest)

ipy_leo: %mb magic and relevant completer for leo minibuffer commands

Workbook.current & match_h LeoNode script method (==tangle), __str__ and __repr__

ipy_leo: minor doc adjustment

freeze_term_title for platutils_posix