We'd like to use a consistent checksum scheme everywhere so that we can:
a) incorporate archive checksums into our specs and have a
consistent hashing algorithm across all specs.
b) index mirrors with a consistent type of checksum, and not one that
is dependent on how spack packages are written.
- [x] convert existing md5, sha224, sha512, sha1 checksums to sha256
- 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
This PR includes the following changes:
* Added JDK 10
* Changed the JDK version numbers according to the consensus reached
in #2284
* Added spec['java'].home and spec['java'].libs, similar to #3367
(JDK and IcedTea)
* Added a check to prevent people from installing JDK on macOS
* Set CLASSPATH for packages depending on Java (JDK and IcedTea)
* Add TODO for extending virtual packages (not currently possible)
* Add TODO for adding Java dependents to views
* Add TODO for packages which extend multiple packages (e.g. Java
and Python)
