- 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
* Adding unzip package.
* Removing bzip2 dependency in unzip and raising an error when on Cray.
* Fixing error.
* Using conflicts statement for Cray detection in unzip package.