
 - I am not sure whether the functional tests are written correctly;
   in particular, I have no idea what to do with the first few entries
   in "ftesting.zcml", and largely copied them from the Grok
   functional testing suite without understanding them.

 - The design needs a Grokker; Trails should register themselves not
   at creation time, but at grokking time, so they can register
   themselves as local rather than global utilities.  They should put
   themselves atop the site they live on, if possible.  Should they
   insist on living on contained objects?

 - Many more tests are necessary.
