When Creating Containers, Public/CDN not enabled by default.

Looks like rackspace is not enabling CDN/Public mode on containers by default, Work around would be to issue ->enableCdn() call on container creation (If this was to be public by default):

```
# /[PROJECT_DIR]/app/Plugin/CloudFiles/Lib/CloudFiles.php
# Add new Line after #354
$Container->enableCdn();  
```

Thanks for creating the plugin!
