* Better docs
* More tests
* More flexibility about where to get the Tangram schema / db connection from.
* Ability to connect if needed..
* Test session saves / restores.
* Mock testing.
* Custom lookups / filters
* Test autoload
* Test stringification
* Test user_results_filter
* Test returning text list of roles.
* Make it throw a hard error (rather than a warning) if you try to search
  the user by an unknown field. 
* Test lookup_roles dealing with both a list and an array ref correctly.