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
The check for if the project supports the -j flag was needlessly
complex. We support two types of project:
- waf, always supports -j
- make, if GNU, supports -j
We never checked waf, and the make check assumed that the entire
command, rather than just the last component, was "make". It also
neglects "gmake".
Since any possible build command *may* support -j, always run the
--version check. Detect either build command in the output.
Dylan Baker