Flip licenses in spec to Debian spec

[pjf]

The debian spec does a better job of specifying all the licenses out there. We should use it, or proxy to it, for our own spec.

[pjf]

The debian spec doesn't distinguish between GPL2 and GPL3. I know I distinguish between them in my head, but I'm not sure if we care enough for the CKAN to care. Also, there's a lot of licenses there which nobody ever releases KSP mods under, which if nothing else means a bit more code clutter.

My expectation is that the biggest uses of the license field is if anyone wishes to make a mirror of all KSP mods, which is an obvious thing to do since a lot of mods became lost or hard to find when spaceport went down, and curse isn't exactly friendly to packaging systems.

[Wizarth]

It doesn't? That's an odd oversight, since they are significantly different.

[pjf]

@Wizarth : Oh! I stand corrected! Debian uses license + version, so GPL-2 and GPL-3are different. Without a number, it implies the earliest version (ie:GPLisGPL-1`).

That probably does make sense, because it means we know the version number as well, and don't need new fields whenever CC comes out with a new version of each thing.

So yes, we probably should shift to Debian-style license fields.

[pjf]

And I'm leaning back the other way on this now. The CPAN::Meta spec combines the license revision into the field itself. This makes it much easier to check using JSON schemas (which we have). The Debian version isn't JSON-schema friendly, unless we make the license number a separate field, and then we end up with a fairly complex layout:
compare:

"license" : [ { "name" => "GPL", version => "2" }, { "name" => "CC-BY", version => "3" } ]

with:

"license" : [ "GPL-2", "CC-BY-3" ]

Although we're possibly fine by using the Debian strings and enumerating all the different license versions in the schema. So GPL-1, GPL-2 and GPL-3 would all validate, but GPL-4 and GPL-3-with-some-clause-removed would not.