Coding standards and output parameters

[Sam Hartman]

I think the requirement looks fine.  It doesn't cover the case where
you explicitly want some output to be available on error--for example
an API token that needs to be sent over the network on error return
might want to be output even if the function does not return success.
Such cases should be clearly documented and until we have a good place
for API docs, that's really hard to do.