MB-6657: off_t ==> cs_off_t

Change-Id: If81d5751a26d73e0d5fb9670b647693bdfaa33e3
Reviewed-on: http://review.couchbase.org/25284
Tested-by: Trond Norbye <trond.norbye@gmail.com>
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: Sriram Melkote <siri.couchbase@gmail.com>
Merge remote-tracking branch 'couchbase/2.0.1' into update

* couchbase/2.0.1:
  MB-6657: off_t ==> cs_off_t

Change-Id: Ib3fd695d8324ef07d24c0b42786d98331e4636a1
Merge "Merge remote-tracking branch 'couchbase/2.0.1' into update" into 2.0.2