Autoscale: Adds envvar AUTOSCALE_KEEPALIVE
ConfigurationView (hence Settings) is a MutableMapping
ConfigurationView (hence Settings) is a MutableMapping
Add note about URL encoding in SQS urls
Merge branch '3.0'

Conflicts:
	celery/datastructures.py
flakes
Merge branch '3.0'

Conflicts:
	celery/datastructures.py