add a groupmeta_collection option to save group results in a different collection than results and add a 'bson' fake kombu encoder to allow pymongo to serialize natively data in mongodb
ghettomq is discontinued
added groupmeta default
Clarify the prefetch multiplier

For years, I thought CELERYD_PREFETCH_MULTIPLIER turned off prefetching, and I had a lot of weird problems.  Today I finally figured out 1 means disabled, 0 means PREFETCH ALL THE THINGS.  This fixes the documentation bug.
Update configuration.rst

I removed duplicates (BROKER_FAILOVER_STRATEGY)
Merge pull request #2187 from tomislater/patch-1

Update configuration.rst
Docs: Improvements to example configuration file /etc/default/celeryd.
Django: Child processes must call django.setup if on Windows (Issue #2126)
Cosmetics
AMQP result backend: Call on_interval every second (always) to propagate parent errors
Merge pull request #2191 from tjanez/improve_example_conf

Docs: Improvements to example configuration file /etc/default/celeryd.
Py3: tests should not depend on mock
Tox: pypy3 must use test3.txt, not test.txt
Merge branch 'master' of github.com:celery/celery
Task: Do not raise retry exception when retry executed in eager mode.  Partially fixes #2164
Fixes tests on py3
Added logging example to redirect stdouts to custom logger in task
Worker: autoreload should ignore not implemented pool.restart.  Closes #2153
Sphinx extension resolved to celery.attr instead of app.attr, also faq referred to outdated celery.execute module
CELERYSA-02 contains invalid workaround advice