Add snapshot support for v1 volume

rebase again, and change util to look for display_name too
minor changes and rebase
add create/delete/list/set/show support for snapshot

Change-Id: I80261653fa919555a44ddda07b0a827ccd16e5e0
Add optional arguments to volume list command

Added --name, --all-tenants, and --status as search params

Change-Id: Ibaa2a7f6862c2ff7dbe24f6bea971db3e70bc120
Merge "Add optional arguments to volume list command"
Merge "Add snapshot support for v1 volume"