validator: Reduce severity of release-time-missing on snapshot releases

[jayaddison]

Resolves #570.

[ximion]

This is not quite what I meant in the bug report...
If there is a date defined, then we should absolutely validate it. But for snapshot releases, having no date shouldn't be an error.

Since there may be a release tomorrow I may just implement that change quickly (but not if the release is deferred to Thursday).

[jayaddison]

@ximion I think that this changeset now adheres more-closely to what you suggested in #570 and here: specifically that although release-time-missing should not be reported as an error for snapshot releases, we should still run the relevant validation and inform users of possible problems.

[jayaddison]

@ximion my communication on this thread was somewhat verbose, so I'll try to be concise: I'd be glad for any code review on the approach currently coded here (approximately: refactor the issue-emission code to allow a severity to be passed by-argument, and use that functionality to emit a reduced-severity (warning instead of error) notice for release-time-missing in the specific case of snapshot releases).

[jayaddison]

Sorry to nag: is this likely to be reviewable in the nearish future? I'm very much not a competent C++ developer, so if the changes initially seem rough/unacceptable, I'd probably prefer to close it and await a more robust implementation.

[jayaddison]

Closing to reduce my mental overhead of open tasks -- not discouraged about reaching a solution for this, just trying to refocus. My eventual hope with resolution of #570 is that I can re-enable the release-time validation for gnome-maps (disabled (hopefully temporarily!) as the warnings conflicted with a build-reproducibility fix).

[ximion]

I am very sorry for getting back to this so late and not supervising this PR properly. I had to take some absence from FOSS development for personal reasons.

But the actual change was trivial, sorry that you put so much more work into it than necessary! It will ship with the next release :-)

[jayaddison]

No problem at all - real life happens, and should take priority.

I'm very grateful for 13a94d5 - yep, I got a bit frantic attempting an implementation, but it was fun to try some C again, and I learned some things :) Thanks again!