Refactor: use cb::io to load couch kvstore stats
Refactor: use cb::io to load couch kvstore stats

Change-Id: I1a39d278f466b4eeccde5bc1e7aa2647a1e15629
Reviewed-on: http://review.couchbase.org/96644
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Dave Rigby <a09264da4832c7ff1d3bf1608a19f4b870f93750@couchbase.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine