Add ability to config from a JSON file
Update appfactories.rst, make extension related section clearer
URL Reversing in Quickstart #779

Updated quickstart to make clear that URL reversing refers to the use of
url_for() to build the URL. Issue #779
Update celery.rst

With the latest version of Celery (3.1.6), following this tutorial produces the following error when attempting to start the celery worker: 

    user_preload = tuple(self.app.user_options['preload'] or ())
AttributeError: 'Flask' object has no attribute 'user_options'

Using `app` as the variable name here confuses celery. Renaming `app` to `flask_app` in the tutorial solves the issue and allows the celery worker to start successfully.
Fixed incorrect grammar in Config.rst

Fixed incorrect grammar in "SESSION_REFRESH_EACH_REQUEST" configuration description.
Fix typo in helpers.py
added a new behaviour for responses that enable the tuple to be in the form of (response, headers) and continiue to support the (response, status, headers) format.
added a new test case with a Response instance and cleaned up the code
Updated greenlet links, which were dead.
Use json method

Use json method of response.Response
Remove unused import
Update fileuploads.rst

secure_filename is under werkzeug.utils (http://werkzeug.pocoo.org/docs/utils/)
Update appcontext.rst

small edit
added a note to the api documentation about JSON_SORT_KEYS. Fixes #922
Explicitly pass the Celery instance name.

When starting a Celery worker module, it is assumed that the Celery instance within the module is called `app`. This is not the case in the Celery pattern, where it is called `celery`, and so must be explicitly referenced.
Update copyright year
Merge pull request #975 from martinp/update-license

Update copyright year in license
Merge pull request #972 from alexpearce/patch-1

Explicitly pass the Celery instance name.
Merge pull request #962 from nZac/JSON-Support-doc-update

added a note to the api documentation about JSON_SORT_KEYS. Fixes #922
Added a warning about key sorting