swap pushers and pullers

also revert previous change

Change-Id: I9ecc4f7ae3493d9e00e885cc7a518c75e64e2bd4
Reviewed-on: http://review.couchbase.org/37009
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>