Use std::limits instead of stdint/ UINT16_MAX
Use std::limits instead of stdint/ UINT16_MAX

Patch only exists as I've a broken debian7 build where this wasn't
defined, yet same source on ubuntu1404 was fine.

Seems cleaner given recent C++ conversions and gets me building again
and hopefully prevents anyone else wasting time if they hit the same
environmental issue I did.

Change-Id: I33b1334ce4717abf0ed3cb6a19688b94305dec7f
Reviewed-on: http://review.couchbase.org/53678
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>

daverigby/memcached,couchbase/memcached,daverigby/memcached,daverigby/memcached,daverigby/kv_engine,daverigby/memcached,couchbase/memcached,couchbase/memcached,daverigby/kv_engine,owendCB/memcached,daverigby/kv_engine,owendCB/memcached,daverigby/kv_engine,couchbase/memcached,owendCB/memcached,owendCB/memcached