Remove use of dynamic buffer for subdoc ops
Remove use of dynamic buffer for subdoc ops

We copy stuff to libevents buffers as we go so we don't need
an extra continuous copy

Change-Id: I8152af5811f6236db89a596c2b01caedd78fb491
Reviewed-on: http://review.couchbase.org/117913
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