filter out irrelevant time wait stats
filter out irrelevant time wait stats

Change-Id: Id56715c950694f20da2fbbdc319e6d258670a115
Reviewed-on: http://review.couchbase.org/33183
Reviewed-by: Pavel Paulau <dd88eded64e90046a680e3a6c0828ceb8fe8a0e7@gmail.com>
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>

couchbase/cbmonitor,couchbase/cbmonitor