CBQE-0: add more logs in CBRecoveryTask

Change-Id: Ibc0920e81809b1dfbaf6e71806dbc67bcb8152ce
Reviewed-on: http://review.couchbase.org/33532
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>