Different strategy. Use cached file list while test panel is closed

package.json

@@ -108,8 +108,8 @@
         "c9.ide.save": "#e00549cb0f",
         "c9.ide.scm": "#0bccfb982b",
         "c9.ide.terminal.monitor": "#b76f1c9f24",
-        "c9.ide.test": "#bf476acc57",
-        "c9.ide.test.mocha": "#3f96974268",
+        "c9.ide.test": "#dac5189891",
+        "c9.ide.test.mocha": "#1cc6097f87",
         "c9.ide.theme.flat": "#2de8414db7",
         "c9.ide.threewaymerge": "#229382aa0b",
         "c9.ide.undo": "#b028bcb4d5",