mon,osd,mgr: add rgw cap profile

rgw keys have been created with mon 'allow rw' and osd 'allow rwx', far
more than the daemon uses. profile rgw grants read on the mon and pg
services, read and write on the osd service, the 'log' command that
carries cluster log warnings, and config-key get under rgw/ on the mon;
rwx on rgw-tagged pools on the osd; and nothing on the mgr. keys take it
as mon 'profile rgw' osd 'profile rgw'. bootstrap-rgw only accepts the
profile.

the osd grant stays service-wide rather than a list of commands because
Rados::pool_create() reaches the mon as MPoolOp, which is checked with
no command name. so it also covers the rest of the osd service's write
commands.

Signed-off-by: Matthew N. Heler <matthew.heler@hotmail.com>