Fix error handling

Note to self: Updates on the session will fail
if ResponseWriter has already been written to
when using cookie store. There should have been
a warning for the very least, but no... I
spent a day or two tracking this insidious bug.
Implement saving of form
Add formatted printing on fora types
Add tid argument
Enforce strict id extraction
Fix nil checks
Update fora tests
Add fora Id getters
Add fora error function
Fix thread reply handler