rgw, radosgw-admin: bucket link uses bucket instance id now

Fixes: 7499
We need to link user to a specific bucket instance. This updates both
the radosgw-admin link command, and the RESTful admin api.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
doc: Admin API usage for quotas. Needs additional clarification on syntax.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: New admin guide for Ceph Object Gateway. Needs some clarification (todo).

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Reworked the simple configuration guide to be more generic.

Changes include removing keystone and putting it into a separate document,
removing user config and putting it into an admin guide, and creating
separate config examples for CentOS/RHEL and Debian/Ubuntu. Needs
clarification on chown/chmod.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Added new docs to index.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Created standalone doc for Keystone Integration.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Distro specific rgw.conf example.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Distro specific rgw.conf example.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Added new cache tiering doc to main docs.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Added new cache tiering doc to index/TOC.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Added cache tiering settings to ceph osd pool set.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Fix hyperlink to CRUSH maps.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
Merge branch 'master' of https://github.com/ceph/ceph into wip-doc-radosgw
Merge branch 'master' of https://github.com/ceph/ceph into wip-doc-radosgw
doc: Added rhel-6-server-optional-rpms repo.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Fixed inconsistent header.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Verified RHEL configuration.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Ensure fastcgi socket doesn't clash with gateway daemon socket.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
osd: track per-pg epochs, min

Add some simple tracking so that we can quickly determine what the min
pg osdmap epoch is.

Signed-off-by: Sage Weil <sage@inktank.com>
osd: prevent pgs from getting too far ahead of the min pg epoch

Bound the range of PG epochs between the slowest and fastest pg
(epoch-wise) with 'osd map max advance'.  This value should be set to
something less than 'osd map cache size' so that the maps we are
processing will be in memory as many PGs advance forward in time in
loose synchrony.

This is part of the solution to #7576.

Signed-off-by: Sage Weil <sage@inktank.com>