* 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
Package repositories now look like this:
top-level-dir/
repo.yaml
packages/
libelf/
package.py
mpich/
package.py
...
This leaves room at the top level for additional metadata, source,
per-repo configs, indexes, etc., and it makes it easy to see that
something is a spack repo (just look for repo.yaml and packages).
