radosgw-admin: check params for object rewrite

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
(cherry picked from commit 28c716bccd955eaf68e9c739139c901ca4f419f7)
radosgw-admin: new 'bucket rewrite' command

Iterates through objects and rewrites them.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
(cherry picked from commit 3af09b9f9f6eaf2c80f0f0fd2ea87ac16c7ffcf8)

Conflicts:
	src/rgw/rgw_admin.cc
radosgw-admin: add some conditions for bucket rewrite

 --min-rewrite-size, --max-rewrite-size to specify object size
 conditions

 --start-date, --end-date to specify object mtime conditions (format is
 YYYY-MM-DD[ HH:MM:SS])

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
(cherry picked from commit dbb2013eaf1eedf2a5cbcae1d314385ea033dbb8)
rgw: update bucket / object rewrite

Get code up to date for firefly, need to pass bucket owner for quota
related functionality.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>