Support RevertLine for lines from previous sessions
Move Ctrl+V entry for Get-PSReadlineKeyHandler output
*SearchHistory to recall current line

Like ordinary recall history, when you use the down arrow, you
eventually recall the current line (which is typically empty
but not always.)

SearchHistory was stopping at the first match instead of getting
back to the current line (which will be exactly the search string.)
Add test to test list
Tweak for easier testing
Reset current history index when done w/ recall

After a series of UpArrow/DownArrow (or whatever keys
are bound to the history search/recall), I am reseting
the current history index.  This avoids a problem where
the current line might not match the line saved in history
for that history index.

There is a small change in behavior that some might notice.
Say you are searching for some command, but you can't think
of something unique to search for in that exact command, but
you do remember something you can search for in a command entered
near that command actual command you want.

Before this change, you could use Ctrl+R to find the command near
the one you want, then use up/down arrows to get to the exact
command.

This will no longer work after this fix.  Any other fix will
likely be more complicated, so if folks ever noticed the previous
behavior and complain that it no longer works.

Fixes #97
Fix small bug with history no duplicates

Up/Down arrow with "no duplicates" would cause an exception
if you tried to go beyond the start/end of history.
Support menu completion

If completion is ambiguous, we will support interactively selecting
the completion using tabs and/or arrow keys after displaying the
possible completions.

This menu style completion can be cancelled with Ctrl+G or Escape.

Menu completion should be optional as not everybody will like it,
I will add an option and/or a function that makes this something
folks can customize.

Also fixed:
    * Tooltips that contain newlines now look much better
    * Undo groups handled a little better (maybe a non-issue before
      menu completion.)