rgw-admin: remove deprecated regionmap commands

[cbodley]

Fixes: http://tracker.ceph.com/issues/18725

[oritwas]

@yehudasa @cbodley removing regionmap get command will mean we no longer support the sync agent (there is no problem removing the set command). If we decide not to support it than it should be documented

[oritwas]

@cbodley as teuthology still test the sync agent we need to remove those tests too.

[cbodley]

@oritwas oh yeah, good point. i guess we should leave the regionmap get command as is, and just remove it from the usage. lets wait to remove sync agent tests until we have test_multi.py working in teuthology

edit: the only calls to region-map get are in tasks/util/rgw.py for get_zone_host_and_port() and get_master_zone(). it looks like we could just reimplement those to use period get

[cbodley]

updated tasks/util/rgw.py (needs testing)

re: support for the sync agent, it looks it's using the admin/config rest api to query the regionmap, so i don't think radosgw-admin commands will break the agent itself

[oritwas]

@cbodley , the moment it passes teuthology we can merge it

[cbodley]

passed teuthology: http://pulpito.ceph.com/cbodley-2017-03-17_11:36:22-rgw-wip-cbodley-testing---basic-mira/

[oritwas]

jenkins test this please