bin: make sure that all options are in a named section
This also fixes some empty lines and unsorted options that appeared in some tools. * tests/sanity/bin.test: Ensure this is done. * bin/README: Add a new paragraph about this. * bin/autcross.cc, bin/ltlcross.cc: Move the output options in their own section. * bin/common_color.cc: Assume color options are in group -15. * bin/common_finput.cc, bin/common_finput.hh: Add a headless variant. * bin/genltl.cc, bin/ltlfilt.cc, bin/ltlgrind.cc, bin/randaut.cc, bin/randltl.cc: Do not force the children groups, so that the options are correctly sorted. * bin/ltlsynt.cc: Add missing groups.