NCBC-684: Rename Couchbase.dll to Couchbase.NetClient.dll

Change-Id: Iffbc2f41554ddef1f6949c2a3280a1beabb8899d
Reviewed-on: http://review.couchbase.org/42378
Reviewed-by: Simon Baslé <simon@couchbase.com>
Reviewed-by: Jeffry Morris <jeffrymorris@gmail.com>
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>