OpenBSD support (fixes #878)

build.sh

@@ -57,6 +57,9 @@ case "${1:-default}" in
 		go run build.go -goos freebsd -goarch amd64 tar
 		go run build.go -goos freebsd -goarch 386 tar
 
+		go run build.go -goos openbsd -goarch amd64 tar
+		go run build.go -goos openbsd -goarch 386 tar
+
 		go run build.go -goos darwin -goarch amd64 tar
 
 		go run build.go -goos windows -goarch amd64 zip

cmd/syncthing/memsize_unimpl.go

@@ -13,7 +13,7 @@
 // You should have received a copy of the GNU General Public License along
 // with this program. If not, see <http://www.gnu.org/licenses/>.
 
-// +build freebsd
+// +build freebsd openbsd
 
 package main