Enable OpenTracing for Windows
Enable OpenTracing for Windows

Change-Id: I48c3b7237f3e151d12146ec3401a6162aba3e7cc
Reviewed-on: http://review.couchbase.org/106553
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