Removing unused and unnecessary functionality.    - show_history is now done at Python level    - get/set completer is not used as C-API calls _completer which      is to be overridden in the Python subclass.
Removing unused and unnecessary functionality.
   - show_history is now done at Python level
   - get/set completer is not used as C-API calls _completer which
     is to be overridden in the Python subclass.

Signed-off-by: Mark Nicholson <8d4a425c9e0ad7c7b6af22eb501c109304c1d477@gmail.com>

mark-nicholson/python-editline,mark-nicholson/python-editline,mark-nicholson/python-editline