Improved broken plugin error logging.
Don't use defer.inlineCallbacks on event handlers.

The decorator's proxy function accepts any number of arguments which
makes signature verification impossible.
Install doc/postgresql/config.sql somewhere.

Where it ends up depends on how you install automatron, but it should
end up somewhere.
Simplify config queries.

(server IS NULL OR server = NULL) will work just fine.
Allow setting new config values.

When calling update_config_value and the value does not yet exist,
insert a new one.
Make PluginManager return STOP when interrupted.
Added role based user permissions.

- Users can be created globally or server wide
- Roles can be created globally
- Permissions can be assigned to roles globally
- Wildcard permission for super admins ('*')
- Roles can be assigned to a user by channel, server or globally
- A user->role assignment is not allowed to have a lower relevance than
  the user itself
Add mechanism for user preferences.