Other port changes:
- Change versioning scheme. Most upstream activity occurs in the master branch, where the latest tag (clisp-2.49.60-2017-06-25) is too old and unwieldy to use for DISTVERSION. Thus, use the same versioning scheme as Debian.
- Remove broken options (GLIBC, JITC, MATLAB, NETICA, ORACLE, THREADS).
- Add test target.
- Pet portclippy/portfmt.