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 *
Use the new CustomGet/CustomPut wrapper mechansim to intercept gets and
puts on CSSStyleDeclaration objects. This allows content to get and set
individual CSS properties from JavaScript. :^)