Log Message:
Update to 0.12

Upstream changes:
Version 0.12
------------

Released on December 21st 2016, codename Punsch.

- the cli command now responds to `--version`.
- Mimetype guessing and ETag generation for file-like objects in ``send_file``
  has been removed, as per issue ``#104``.  See pull request ``#1849``.
- Mimetype guessing in ``send_file`` now fails loudly and doesn't fall back to
  ``application/octet-stream``. See pull request ``#1988``.
- Make ``flask.safe_join`` able to join multiple paths like ``os.path.join``
  (pull request ``#1730``).
- Revert a behavior change that made the dev server crash instead of returning
  a Internal Server Error (pull request ``#2006``).
- Correctly invoke response handlers for both regular request dispatching as
  well as error handlers.
- Disable logger propagation by default for the app logger.
- Add support for range requests in ``send_file``.
- ``app.test_client`` includes preset default environment, which can now be
  directly set, instead of per ``client.get``.

Version 0.11.2
--------------

Bugfix release, unreleased

- Fix crash when running under PyPy3, see pull request ``#1814``.

Version 0.11.1
--------------

Bugfix release, released on June 7th 2016.

- Fixed a bug that prevented ``FLASK_APP=foobar/__init__.py`` from working. See
pull request ``#1872``.