[plt-scheme] web-server exceptions and continuation barriers

More woes from the v208 -> v299 upgrade:

I use `(report-errors-to-browser send/back)' in most of my servlet
code, so I get an error page when an exception is raised while running
a servlet.  But now I'm also getting the following printed to stderr:

exception raised by exception handler: continuation application: attempted to cross a continuation barrier; original exception raised: reference to undefined identifier: make-response/full

It doesn't seem to be a fatal error, but it's an ominous-sounding
message.  Should I be worried?

[By the way, in case you're playing along at home,
`make-response/full' is now in "response.ss".]

--dougo at place.org