Bobg is working on most of this set of tasks:

get rid of ufile, review tables (I see unique constraints on columns that can take null), use cascades to remove uploads, ...

**Specifically**:

  * Remove ufiles in database
  * Migrate to using nested sets
  * Change most of the UI code so that it uses these new fields
  * Change unpack agent to use the new nested sets
  * Modify scheduler.conf (sqlagent goes away, new agent)
  * Changing the schema in the init plugin to upgrade an existing installation
  * Update developer documentation
  * Update user documentation