improvements to get the HHVM build to pass

tst/bootstrap.php

@@ -1,5 +1,6 @@
 <?php
 error_reporting( E_ALL | E_STRICT );
+ini_set('hhvm.xenon.period', '0');
 
 // change this, if your php files and data is outside of your webservers document root
 if (!defined('PUBLIC_PATH')) define('PUBLIC_PATH', '..');
@@ -256,4 +257,4 @@ class helper
             return var_export($var, $return);
         }
     }
-}
+}