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/benchmark-integration.sh

@@ -40,7 +40,7 @@ runTests() {
     KUBE_TEST_ETCD_PREFIXES="registry" \
     ETCD_CUSTOM_PREFIX="None" \
     KUBE_TEST_ARGS="${ARGS}" \
-    "${KUBE_ROOT}/hack/test-go.sh" test/integration
+    make test WHAT=test/integration
   cleanup
 }