PG: dirty_info on handle_activate_map

We need to make sure the pg epoch is persisted during
activate_map.

Backport: bobtail
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Samuel Just <sam.just@inktank.com>
(cherry picked from commit dbce1d0dc919e221523bd44e1d0834711da1577d)
ReplicatedPG: check store for temp collection in have_temp_coll

We may not have "created" the temp collection since OSD restart
before removing the PG.  have_temp_coll must also look at the
OSD store.  Currently, the only user is pg removal, so the
extra work is acceptable.

Backport: bobtail
Signed-off-by: Samuel Just <sam.just@inktank.com>
(cherry picked from commit fa47e77a13156a272fece698e677dcd4f9884a5b)
OSD::load_pgs: first scan colls before initing PGs

Backport: bobtail
Signed-off-by: Samuel Just <sam.just@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 55f857962fc584e7e95babbd10a3c53aab63060a)
OSD: check pg snap collections on start up

Backport: bobtail
Signed-off-by: Samuel Just <sam.just@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
(cherry picked from commit ed2bb387708511b4910758d77c5a9754193eb48a)