* module/mes/getopt-long.scm (remove-if-not): Remove.
(option-spec): Add value field. Update users.
(expand-clumped-singles): Simplify, fix.
(process-options): To get an option's value, use value instead of
value-policy. Fixes multi-opt.
* tests/getopt-long.test: New file.
* make.scm (mes-tests): Add it.
* check.sh (tests): Add it.
* tests/getopt-long.test-guile: New symlink.
