fix all tests to run with node.js

lib/ace/test/virtual_renderer_test.js

@@ -36,10 +36,11 @@
  * ***** END LICENSE BLOCK ***** */
 
 require("../../../support/paths");
+require("./mockdom");
 
-var Document        = "../document",
-    VirtualRenderer = "../virtual_renderer",
-    assert          = "../assertions";
+var Document        = require("../document").Document,
+    VirtualRenderer = require("../virtual_renderer").VirtualRenderer,
+    assert          = require("./assertions");
 
 var Test = {
     "test: screen2text the column should be rounded to the next character edge" : function() {