ceph, librados, rados.py, librados tests: pass cmd as array

ceph, librados, rados.py, librados tests: pass cmd as array

Using ceph to pass commands to the old monitor requires the
message to have words in a vector; this means that we need to pass
the command as an array to rados_mon_command.  Really, all of the
rados_X_command functions should take an array for flexibility and
parallel structure, so change them all, and the Python bindings,
and the test programs that use them.

Signed-off-by: Dan Mick <dan.mick@inktank.com>