CBQE-1101: attach postcondition handler at prerun

Change allows specifying which condition checking
method should be picked up by the postcondition_handler
when a workload is started

Change-Id: I54f2a2b956bd8f006e80405efb042d878a130a78
Reviewed-on: http://review.couchbase.org/25175
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Chisheng Hong <chisheng@couchbase.com>
CBQE-1129: remove worker atop collection

Stat collection is now being handled entirely by cbmonitor.

Change-Id: Ic7f60bbbe3806fc43bd46dafb4537f9d06c63543
Reviewed-on: http://review.couchbase.org/25176
Reviewed-by: Chisheng Hong <chisheng@couchbase.com>
Tested-by: Tommie McAfee <tommie@couchbase.com>
CBQE-966: define index_key in query workload

this change makes it so that indexed_key can be defined
in query workload.  previously the template needed to
be defined and this template had indexed key.

Change-Id: I9326776f0df66c23de2538d825ce2c4fb634d706
Reviewed-on: http://review.couchbase.org/25207
Reviewed-by: Tommie McAfee <tommie@couchbase.com>
Reviewed-by: Chisheng Hong <chisheng@couchbase.com>
Tested-by: buildbot <build@couchbase.com>