This modules allows you to use the private-storage feature of jabber with djabberd.

This is often used to bookmark MUC room, or store annotation about your contact. This 
can also be used by bots, to store various data, or by jabber client, to store their
settings.

The module is using the same model as other plugins. A base class called 
DJabberd::Plugin::PrivateStorage take care of the detail, and must be subclassed, 
and two method must be overloaded, in order to provides a real backend. 

Currently, 3 backends are shipped :
- DJabberd::Plugin::PrivateStorage::InMemoryOnly
  This module is here for testing and to serve as example. 
  Everything is stored in memory, and do not survive to the reboot.
 
- DJabberd::Plugin::PrivateStorage::SpoolDirectory
  This module use a simple directory system, to store the private storage
  content.

- DJabberd::Plugin::PrivateStorage::DBI
  This module use DBI to access to a supported database.
