This replaces all of the Apache blurbs at the start of each file with an
`# SPDX-License-Identifier: Apache-2.0` string. It also fixes existing
uses to be consistent in capitalization, and to be placed above any
copyright notices.
This removes nearly 3000 lines of boilerplate from the project (only
python files), which no developer cares to look at.
SPDX is in common use, particularly in the Linux kernel, and is the
recommended format for Meson's own `project(license: )` field
Merging snippets happens in arbitrary order -- whatever filesystem
globbing results in. This didn't matter too much when we ran it once at
release time and checked the resulting release notes into git. However,
now that we generate a temporary version of the release notes for
development versions, the order of the results will periodically change.
Sort the files before processing them in order to guarantee that
whatever order they are in, they stay that way.
As a side effect, it's now technically possible to guarantee an ordering
by judicious use of snippets naming.
Dylan Baker