Flask-gravatar

- Try to read configuration values from application config if a context
is available otherwise return an instance config or extension default.
(pull 23)
- Package refresh - testing Python 3.6, fixed links, and much more.
(pull 22)

- Set use_ssl default value according to request protocol. (pull 14)
- Improved documentation typo fixes. (pull 13 18)
- Migration from flaskext.gravatar to flask_gravatar. (pull 11 12)

- Added Python 3 support. (pull 9)

- Added custom url support. (pull 7)
- Use setuptools. (pull 6)

- Enabled registering multiple times in one process.

- Added init_app method.
- Fixed various bugs.