fix rake commonjs

mustache-commonjs/mustache.js.tpl.post

@@ -0,0 +1,7 @@
+
+exports.name = Mustache.name;
+exports.version = Mustache.version;
+
+exports.to_html = function() {
+  return Mustache.to_html.apply(this, arguments);
+};

mustache-commonjs/mustache.js.tpl.pre

@@ -0,0 +1,6 @@
+/*
+ * CommonJS-compatible mustache.js module
+ *
+ * See http://github.com/janl/mustache.js for more info.
+ */
+