Exercise cleanup

* Make common steps consistent
* Make comments consistent

boot_from_volume.sh
euca.sh
floating_ips.sh
sec_groups.sh
swift.sh
volumes.sh

Change-Id: Ib93dcdfdead93c259e3cd184fbc5ccc0a4a87c9a
Merge branch 'init-split' into dt-test
Merge branch 'nova-config-cleanup' into dt-test
Merge branch 'database-service' into dt-test
Merge branch 'clean-ex' into dt-test