Add version validation to Release tooling

[dd32]

The WordPress.org release management tooling currently trusts the user filling out the forms, and prefills/includes details about what it's going to release, but it's easy to forget / miss something.

For example, today beta4 was originally packaged as 5.6-beta4-49588 rather than 5.6-beta4, a mistake that has happened numerous times before (Sometimes due to core.svn builds being delayed, others just mistakenly not bumped the right digits).

In the past we've also had x.y-Beta1 (should be lowercase, unlike x.y-RC1) and also minor versions skipped (ie. releasing x.y.3 -> x.y.5 instead of x.y.4, unintentionally skipping a digit), both of which should easily be prevented with some simple version checking in the UI.

There's also some checks in place to work with/prevent the re-releasing of packages, so more UI around "This doesn't quite look right, are you sure?" would benefit others in the future.

cc @helen and @SergeyBiryukov since you've been doing most releases lately, is there anything else that comes to mind that I've missed here? If it's something that human eyes can say "That doesn't look quite right" then surely some big red text to that effect wouldn't go astray :)

[helen]

An AYS saying "that doesn't seem right, are you sure?" and maybe some text on the packaging screens to remind you what the expected formats are would be good... longer term I would love if we could automate the bump commits a little.

[SergeyBiryukov]

Replying to dd32:

is there anything else that comes to mind that I've missed here?

One other thing that comes to mind is that it would be great to have a link to the ZIP package after building.

Currently it does that for nightly builds:

Nightly for trunk refreshed.
​http://wordpress.org/nightly-builds/wordpress-latest.zip

But not for beta/RC/final packages. For those I currently have to go to ​https://wordpress.org/download/releases/ and grab the link from there.