Fix socket leaking for completion-based backends (libuv, iocp)
Fix socket leaking for completion-based backends (libuv, iocp)

Change-Id: I384e63bf278bca05b257a5fa6a09862de3bf55fa
Reviewed-on: http://review.couchbase.org/119264
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Ellis Breen <9d8041ac7ead8d3e1f3217c04c7ed5e3098c2381@couchbase.com>

couchbase/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,kojiromike/libcouchbase