Upgrade notes 0.9

Some important things to run smoothly and gotchas to watch out for...

Database

 * (new tables...)
 * (new indexes...)
 * 08to09.sql

Twitter integration

 * has moved to a plugin:
 * addPlugin('TwitterBridge');

OpenID

 * has moved to a plugin:
 * addPlugin('OpenID');

Sphinx search

 * Has moved to a plugin:
 * addPlugin('SphinxSearch');
 * new index names to support multiple switching; need to reindex at least once!
 * scripts renamed...