Common metadata state is now stored
Optimistic locking support added to common_metadata
Revisions to keys in project metadata are now reflected in the project state
Wrote tests for project metadata (all pass)
Relaxed test conditions to work on projects with extra keys
Added documentation for project metadata
Additionally:
Update CHANGELOG
Make cooldown period optional for autoscaler
Refactor autoscaler and add more error checking
Instance template now supports image aliases
Replace instance group manager 'size' -- use target_size (now writeable)
Add documentation for autoscaler
Add beta warnings to docs