Reconsider handling of '/foo' vs '/foo/' routes.

[davidsoergel]

Currently _clean_path() strips trailing slashes before further processing a route. This has pitfalls, which could be avoided by instead serving a redirect.

See discussion on #2476.

[nfelt]

Fixed by @wchargin in #2734.

[davidsoergel]

#2734 fixes only the case of an empty path at the root level, not /foo/, so per the discussion on #2476, this issue is still outstanding. Of course, it may be a lower priority, and/or the resolution may end up being that we do nothing :)

[nfelt]

Fair point, thanks for the reminder.