Pillow no longer has a _makeself() method #1
Description
As of Pillow 4.0.0 (2017-01-01), _makeself() was replaced by _new: https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst#400-2017-01-01
Use Image._new() instead of _makeself() #2248 [homm]
Issue: python-pillow/Pillow#2248
Changing the two references in palette.py from _makeself to _new makes hitherdither work with recent Pillow releases.