allow baking tests for controllers with uses

if a controller has

	public $uses => array('MyPlugin.MyModel')

in their controller - the bake controller task will fail because `$controller->MyPlugin.MyModel`
doesn't exist

lib/Cake/Console/Command/Task/TestTask.php

@@ -390,6 +390,7 @@ class TestTask extends BakeTask {
 			$models = $subject->uses;
 		}
 		foreach ($models as $model) {
+			list($plugin, $model) = pluginSplit($model);
 			$this->_processModel($subject->{$model});
 		}
 	}