More Robust AVC Version Handling

[dbent]

This PR makes the handling of version information found in internal .version files more robust. In practical experience the internal .version files aren't remarkably accurate, so we make the two following changes:

• If the metadata already contains a version field, such as from KerbalStuff or a GitHub tag, we do not override it with the value found in the .version file.
• KSP version information is calculated by "merging" the values that are already in the metadata and what we find in the .version file. A common example would be if some mod on KerbalStuff indicates that it's compatible with a version of KSP later than what it specifies in its .version file. In that case we calculate a minimum version from the .version file and a maximum version from the KerbalStuff metadata.
• Add support for "build" component in AVC version, only added if present.

The CorrectlyCalculatesKspVersionInfo test contains a lot of cases. Please add any additional cases you think requires testing.

[pjf]

You are the best.

[JennDahm]

Would it be possible to indicate that we'd like for the AVC version to overwrite the GitHub version? I don't think the version tags I've been using in my project on GitHub aren't quite CKAN friendly (ex: "v0.1.1-alpha", rather than "0.1.1"), and it'd be nice if I could correct this via the AVC file I'm creating rather than recreating all the release tags.

[mheguy]

@JonDahm For what it's worth we see quite a bit of v coming and going from one version to the next but thankfully have tools to work around that.

[JennDahm]

Just to be clear, you're saying that versions formatted with a v in front of the number work just as well as those without? If so, that's great and I don't have to worry about the version numbers comparing correctly.

[mheguy]

It's not automatic, we have to add a flag and that flag automatically adds v to every version (so they're uniform). Because it's manual it means someone has to 'catch' that the v is inconsistent. If you have mods that you know use v intermittently just let us know and we can correct it.

[JennDahm]

Ah, okay. But so long as I use the v consistently, there shouldn't be a problem, correct?

[mheguy]

Correct.

[dbent]

And if you really want to strip the v or other misc parts, #1321 will be an option.

[JennDahm]

Got it. Thanks a bunch!

[pjf]

This is really clever, thank you! :)

[pjf]

@dbent : I'm so sorry this has been hanging so long, I'm still playing catch-up after being overseas, but this looks fantastic. Merging with great thanks!