- [x] add `concretize.lp`, `spack.yaml`, etc. to licensed files
- [x] update all licensed files to say 2013-2021 using
`spack license update-copyright-year`
- [x] appease mypy with some additions to package.py that needed
for oneapi.py
- remove the old LGPL license headers from all files in Spack
- add SPDX headers to all files
- core and most packages are (Apache-2.0 OR MIT)
- a very small number of remaining packages are LGPL-2.1-only
* Merged 'purge' command with 'clean'. Deleted 'purge'. fixes#2942
'spack purge' has been merged with 'spack clean'. Documentation has been
updated accordingly. The 'clean' and 'purge' behavior are not mutually
exclusive, and they log brief information to tty while they go.
* Fixed a wrong reference to spack clean in the docs
* Added tests for 'spack clean'. Updated bash completion.
* Fix various documentation bugs
* Keep long option names, but don't include in Command Index
* Use long option name
* Explicitly designate sections to be listed in the Command Index
* Consistent menu bar titles
