- 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
* Remove +mpi variant from NCO
* Update NCO deps to AutotoolsPackage
* Update the other NetCDF packages to AutotoolsPackage
* ANTLR has a nolink deptype on java, don't worry about csharp
* Remove restrictions from NCO package, fix homepage
* Add version 4.6.3 of NCO
* Missed AutotoolsPackage for NetCDF-CXX4
* NetCDF tests fail when run in parallel
* Remove commented out dependency
* Add documentation dependency