CBLT-170:  Sync Gateway is now packaged as an installer, not a ZIP.

Change-Id: Iaf996520468b36b2bf40f8d5bdad7547af0bc830
Reviewed-on: http://review.couchbase.org/35714
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>