Bumps version to 3.0.20
events.State: Ignore unknown events
Last commit broke events.State pickleability
chord_unlock now uses default_retry_delay
Now depends on billiard 2.7.3.29
Now depends on billiard 2.7.3.30
Makes qualname work when module already in name
Now depends on kombu 2.5.12
Updates Changelog
flakes
Mediator thread should only be started for processes pool.  Closes #1457
Provide citation for Art of Concurrency section about task granularity.  Closes #1453
Now depends on billiard 2.7.3.31
Fix gevent connection leak

Using CELERYD_POOL of gevent can cause a connection leak.
Cleaning up the cached_properties prevents that.
Fix gevent connection leak

Using CELERYD_POOL of gevent can cause a connection leak.
Cleaning up the cached_properties prevents that.
Updates Changelog
Bumps version to 3.0.21
Merge branch '3.0'

Conflicts:
	Changelog
	README.rst
	celery/__init__.py
	celery/events/state.py
	celery/utils/imports.py
	celery/worker/__init__.py
	docs/includes/introduction.txt
	requirements/default.txt
	setup.cfg
review
Merge branch 'master' of github.com:celery/celery