rgw.py: refactor configure
rgw.py: refactor configure

Extend the rados pool configuration options to
specify all pools (if desired).
Also, reordered zone and region configuration
so that they're configure (per client) in
this order: zone, region, set default region

Signed-off-by: Joe Buck <a95e51950b61b017a762bcc8a962bac0b1a073a0@gmail.com>

dreamhost/teuthology,dmick/teuthology,SUSE/teuthology,ivotron/teuthology,robbat2/teuthology,dmick/teuthology,ceph/teuthology,t-miyamae/teuthology,zhouyuan/teuthology,tchaikov/teuthology,ktdreyer/teuthology,michaelsevilla/teuthology,ktdreyer/teuthology,yghannam/teuthology,dmick/teuthology,t-miyamae/teuthology,caibo2014/teuthology,SUSE/teuthology,robbat2/teuthology,yghannam/teuthology,zhouyuan/teuthology,ceph/teuthology,ivotron/teuthology,tchaikov/teuthology,caibo2014/teuthology,michaelsevilla/teuthology,dreamhost/teuthology,SUSE/teuthology