Bundle libcouchbase.dll when building on Windows

Change-Id: Ia5a20fb0c2d87a65d69d506646d97ec760881051
Reviewed-on: http://review.couchbase.org/27032
Reviewed-by: Matt Ingenthron <matt@couchbase.com>
Tested-by: Mordechai Nunberg <mnunberg@haskalah.org>