Fix initial creation of directory for history file.
Update help for history saving options
Fix a typo
Fix ShowKeyBindings to not write blank lines
Fix exception when setting history save path
Change a couple key bindings

Bind MenuComplete to Ctrl+Space in Windows and Emacs mode
Bind YankLastArg to Alt+. in Windows mode
Attempt better recovery from an exception

If an exception occurs when editing the command line, display some
diagnostic information so that I might get a bug report.  Also
attempt to restore the command line so they can continue editing.
Change parenthesize sample to honor selection
Fix tests for recent changes
Fix undo bug

There was a bug in undo code where if you undid some stuff, made an edit,
then started a grouped edit, the undo state was incorrect.  A simple
repro was something like (in Windows mode)

    a b c d Ctrl+z Ctrl+z Ctrl+z Shift+LeftArrow Ctrl+x
Update version # and change log for 1.0.0.10