[albatross-users] Wiki example and related extension: iterate over ctx/session

[Gregory Bond]

> Dave's suggestion is pretty gross. I wonder if we should put a
> session_vars() method on the context that returns a list of session vars?

It sure wouldn't hurt, but it's not ideal - because in order to access the 
sessions names from a template, you need to put them into the ctx.locals - and 
do it at just the right time in the process so that you get the correct answer.
(session_vars() will return a copy, so won't be updated as session vars are 
added/deleted.)

This also means in order to put debugging in, you need to edit the page_display
function as well as the template.

The advantage of having the session dict in the ctx.locals is that you can do 
debugging by justy changing the template, and it will be up to date as no 
copies are involved.