In order to allow replication sets to be all on the same hypervisor
(affinity) or all on different hypervisors (anti-affinity) a new
argument (locality) needed to be added to the Trove create API.
This changeset addresses the Trove client part of this feature.
A --locality flag is now available on the 'create' command and
is passed to the server for processing.
The --replica_count argument was also cleaned up in that it's not
passed on unless it is set. If --replica_of is specified, the
default is set to '1.'
DocImpact: New functionality
Partially implements: blueprint replication-cluster-locality
Change-Id: I18f242983775526a7f1e2644302ebdc0dac025cf
358dbf3c80