Disable amqp heartbeats by default
flakes
Fixes syntax error in example
Better kvstore chord unlock error handling
Py3 fixes
Better chord unlock error handling for kvstores
Tests passing
Merge branch '3.0'

Conflicts:
	celery/app/base.py
	celery/app/builtins.py
	celery/backends/base.py
	celery/tests/worker/test_hub.py
	celery/worker/consumer.py
	celery/worker/hub.py