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/update-swagger-spec.sh

@@ -33,7 +33,7 @@ source "${KUBE_ROOT}/hack/lib/init.sh"
 
 kube::golang::setup_env
 
-"${KUBE_ROOT}/hack/build-go.sh" cmd/kube-apiserver
+make -C "${KUBE_ROOT}" WHAT=cmd/kube-apiserver
 
 function cleanup()
 {