Additions and changes:
- update xdebug reference to 2.2.2
- update mongo reference to 1.3.6

Bug fixes:
- GH-72: Namespace issue
- GH-76: broken extension report (thanks to Remi Collet)
- GH-77: Allow to use Environment variable in cache 'save_path' option (thanks to Remi Collet)
- GH-80: Issue apcu (thanks to Remi Collet)
