docs: README markup fixes#
bumped version numbers
style: PEP8 fixes
docs: fix configuring priximity index tutorial

closes #71
docs: fix indexes tutorial missing section

Complete truncated sections on configuring indexes with `sortStore`
setting.
bugfix: BdbIndexStore UnicodeDecodeError when logging

fixes #72
docs: fixed internal README link
docs: updated CHANGES file
Bugfix release 1.0.15

Merge branch 'hotfix/1.0.15'
docs: updated README date
docs: updated README date
Merge branch 'hotfix/1.0.15'
Merge tag '1.0.15' into develop

Bugfix release 1.0.15

See CHANGES file for details.

Conflicts:
	CHANGES.rst
	VERSION.txt
	cheshire3/__init__.py
	cheshire3/internal.py
	docs/source/tutorial/indexes.rst