Flask-blogging

- Fixed a bug in the edit post routines. The edited post would end up as a
new one instead.

- The ``SQLAStorage`` accepts metadata, and ``SQLAlchemy`` object as inputs.
This adds the ability to keep the blogging table metadata synced up with
other models. This feature adds compatibility with ``Alembic`` autogenerate.
- Update docs to reflect the correct version number.

- Permissions is a new feature introduced in this version. By setting
``BLOGGING_PERMISSIONS`` to ``True``, one can restrict which of the users
can create, edit or delete posts.
- Added ``BLOGGING_POSTS_PER_PAGE`` configuration variable to control
the number of posts in a page.
- Documented the url construction procedure.

- ``BloggingEngine`` ``init_app`` method can be called without having to
pass a ``storage`` object.
- Hook tests to ``setup.py`` script.

- ``BloggingEngine`` configuration moved to the ``app`` config setting.
This breaks backward compatibility. See compatibility notes below.
- Added ability to limit number of posts shown in the feed through
``app`` configuration setting.
- The ``setup.py`` reads version from the module file. Improves version
consistency.

- Added Python 3.4 support