The new one is the same as the old one, just in the new Parser's
source files. This isn't the most elegant solution but it seemed
like the best option. And it's all temporary, after all.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
