extracted code to scale up and down to a shared, more generic method
Merge remote-tracking branch 'org/testing' into scale-appservers-down
added initial checks for when scaling down is appropriate
refactored terminate instance interface in iaas manager to be more friendly to callers, and added code to downscale as needed
added code to terminate gce instances back into iaas manager, for when downscaling is needed
not scaling down below the minimum number of VMs the user sets
properly comparing min images, and correctly deleting old scaling info
only scaling down if we haven't recently scaled up, and properly removing node info from all nodes when we downscale
not waiting for flower port to open after we start it
fixed broken unit test
Merge pull request #592 from shatterednirvana/scale-appservers-down

Scale appservers down