rechecks are silently ignored if the comment is against an older version

[Robert Collins]

This may sound like correct behaviour, but actually its fairly easy to end up on an older versions 'add comment' form, and the complete lack of feedback means that zuul appears to be flaky, rather than being 'correct'.

In a discussion with fungi on IRC we couldn't come up with any reason not to just use the latest patchset for recheck actions, for ease of use:

07:08 < fungi> lifeless: probably worth a wishlist bug for zuul to translate the patchset number in the comment
               via a lookup to find out what the latest patchset for that change is, rather than simply
               ignoring it outright
07:09 < fungi> lifeless: there may be unforseen interactions resulting from that, but at the moment none come
               to mind

So to whit, one wishlist bug.

[Jeremy Stanley (fungi)]

Given the genericity of the comment handler, this would likely need to be a configurable toggle so you could set specific comment triggers to assume latest patchset or something along those lines.