[arch-dev-public] Using SPDX License list as identifiers

[Jerome Leclanche]

Hi

This just came up on IRC. Thoughts on using the SPDX license list as valid
license identifiers for all packages?
https://spdx.org/licenses/

Most of the identifiers would change but we would have a consistent and
much larger, externally-maintained list to choose from. It would also be a
little more accurate; eg. the SPDX allows for distinctions such as
"LGPL-3.0-or-later" vs. "LGPL-3.0-only".

We could retain the current identifiers as symlinks.

J. Leclanche