modified config for consistency in php-shindig

[panjie . pan]

Reviewers: shindig-dev, chabotc,



Please review this at http://codereview.appspot.com/24086

Affected files:
  php/config/container.php
  php/src/common/Cache.php
  php/test/common/CacheFileTest.php
  php/test/common/CacheMemcacheTest.php