Integrated vfsStream better and made paths constants VFS-based

Signed-off-by: dchill42 <dchill42@gmail.com>
diff --git a/tests/codeigniter/helpers/date_helper_test.php b/tests/codeigniter/helpers/date_helper_test.php
index 9feade7..1458acd 100644
--- a/tests/codeigniter/helpers/date_helper_test.php
+++ b/tests/codeigniter/helpers/date_helper_test.php
@@ -168,6 +168,8 @@
 
 	public function test_timespan()
 	{
+		$this->ci_vfs_clone('system/language/english/date_lang.php');
+
 		$loader_cls = $this->ci_core_class('load');
 		$this->ci_instance_var('load', new $loader_cls);