Use make as the main build tool

This allows us to start building real dependencies into Makefile.

Leave old hack/* scripts in place but advise to use 'make'.  There are a few
rules that call things like 'go run' or 'build/*' that I left as-is for now.

hack/local-up-cluster.sh

@@ -78,9 +78,7 @@ do
 done
 
 if [ "x$GO_OUT" == "x" ]; then
-    "${KUBE_ROOT}/hack/build-go.sh" \
-        cmd/kubectl \
-        cmd/hyperkube
+    make -C "${KUBE_ROOT}" WHAT="cmd/kubectl cmd/hyperkube"
 else
     echo "skipped the build."
 fi