Discovered and worked around a problem that will have to be solved much more generally:
  For now, allow only the commands outside the body pane: 'Y', 'P', 'z' ,'colon' ,'question', 'slash'.
  This is due to an overly restrictive test in vc.do_key.
  In fact, there is an opportunity here: commands could do different things in the tree than they do in the body.
  For example, h ,j ,k, l, y and p have obvious meanings in the tree pane.

Many tweaks and additions:
- Corrected entries in dispatch dicts to use Leo/Tk stroke spellings.
- Added ^ command.
- Added p, P, y and Y commands.  Note: P and Y paste and yank Leo outlines.  But see above for a better way.
- Fixed repeat count problems.
- v ending visual mode no longer clears the outline. This is a much better fit to Leo's legacy commands.
Merge branch 'master' of github.com:leo-editor/leo-editor