...by not using its own-rolled getopt, and moving the `list' function
to a separate script
* meta/guile-tools.in: Use (ice-9 getopt-long).
(directory-files, strip-extensions, unique, find-submodules,
list-scripts): Deleted (and moved to new `list.scm' file).
(getopt): Deleted.
(main): Use getopt-long. Default to calling the `list' script if no
script is specified.
* module/scripts/list.scm: New script.
* module/Makefile.am (SCRIPTS_SOURCES): Add list.scm.
