Add a generic script to run the right Node binary

(imported from commit cf187323786cf1ee576ec70b6f7db4cbf61d6911)

tools/node

@@ -0,0 +1,11 @@
+#!/bin/bash -e
+
+# Wrapper for node which finds the right binary.
+
+if which nodejs >/dev/null; then
+    # Name used by Debian etc.
+    exec nodejs "$@"
+else
+    # Name used by upstream
+    exec node "$@"
+fi