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'