deb: Some copyright improvements

[Finii]

[why] The license identifiers are not always the standard SPDX form.

See:

• https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/#license-short-name
• https://spdx.org/licenses/

[Finii]

Btw, I have no clue what we need to put into out LICENSE file.

[alt-graph]

When I look at https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/#license-specification , I'd think that the names in the table are the preferred ones? And below the table, it specifically states

There are many versions of the MIT license. Please use Expat instead, when it matches.

So I thought that would have been OK? But you are much deeper in Debian packages than I am... :shrug:

[Finii]

Hmm, to be honest: I don't know.

The use Expat notice is there from the beginning, i.e. since 2012. There was some confusion what MIT would mean. I always use the SPDX specifier only, for example also CC0-1.0 instead of CC0.

Probably you are right.