- 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
* Ensure that every package has a license
Also fixes URLs with http://http:// doubled.
This is a continuation of #2656.
* Add license to every file in Spack
* Make sure Todd is the author of all packages
* Fix flake8 tests
* Don't license external Sphinx docs
* Don't display licenses in tutorial example packages
Also fixes typos and converts command-line examples
from tcsh to bash, which is more common
