AUTO-816: Disconnecting from cass on shutdown

LoggingCQLClient.disconnect is implemented in silverberg 0.1.6. Hence
the version upgrage
kazoo client is stopped on shutdown
lint fix
service super methods called - thanks @glyph
Add a desired capacity column 'desired' to the scaling group table
trying disconn after supervisor jobs are completed
Merge branch 'master' into auto-816-cass-disconn

Conflicts:
	otter/tap/api.py

Combined health checker info
removing duplicate multiservice creation
Merge branch 'auto-816-cass-disconn' into cass-disconn-try

Conflicts:
	otter/tap/api.py
no need for nofify_on_jobs_completion

Can use stopService instead
cassandra_disconnect implemented

that disconnects after supervisor completes stopping
updated tests for cassandra_disconnect
Use varint instead of int, since int is 32 bit signed (and silverberg currently cannot unmarshal it) and there is no need to be specific
Not using supervisor.stopService - thanks @cyli

when disconnecting from cassandra since it assumes that stopService is
idempodent which we don't know.
Merge pull request #512 from rackerlabs/auto-816-cass-disconn

AUTO-816: Disconnecting from cass on shutdown
Merge branch 'master' into auto-817-kz-stop
tests updated for stop changes
Comment about int vs varint in the schema
Merge pull request #528 from rackerlabs/auto-817-kz-stop

AUTO-817 Stopping kazoo client during shutdown
Up the default polling frequency for polling nova server status to avoid 413's