- 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
* treesub: new package starting at 0.2
* treesub: fix ant build, add exec script
* treesub: use portable octal format
* treesub: add license header
not sure how it even went missing.