- [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
* SourceForge: Mirror Mixin
Add a mixing class for direct `CNAME`s to sourceforge mirrors.
Since the main gateway servers are often down, this could reduce
timeouts and fetch errors for sourceforge.net hosted software.
* SourceForge: unspectacular mirror replacement
add mirrors to all sourceforge packages with trivial
download logic.
tested fetch of latest version of each of these packages
with various mirrors before committing.
* SourceForge: xz
the author homepage is chronocially overrun and this is the offical
upload with many mirrors.
