CBQE-0: remove _all prefix from estat response

Change-Id: I07af1c4537cb7b45715532f0342524c90e696c47
Reviewed-on: http://review.couchbase.org/27253
Reviewed-by: Tommie McAfee <tommie@couchbase.com>
Tested-by: Tommie McAfee <tommie@couchbase.com>