The bash completion code is the sole user of the slugify() function
in utils, which is substantially similar to to_slug() provided in
strutils from oslo. Remove slugify() and use to_slug() instead.
Change-Id: Iffab2f59504ee7ec6528860e06a5140ff22f332f
Closes-Bug: #1266127
Adds command 'metadata' for setting and unsetting metadata keys.
Adds command 'metadata-update-all' for updating all metadata.
Adds command 'metadata-show' for viewing share metadata.
Adds key '--metadata' to command 'create'
Partially implements bp manila-client-enhancements
Change-Id: I10d20e12e71065d6e40be062715fa01998828ab2