The `TextEditor::on_change` callback now only fires if the user types in
the box, or `set_text()` is called with `AllowCallback::Yes`.
Previously that callback was what set `m_color`, so I've rearranged
things a little so that the color still updates regardless of what
source the color came from.
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 *
