For PR automake/414: Introduce option filename-length-max=99. * doc/automake.texi (Options): Document it. * configure.ac (AM_INIT_AUTOMAKE): Use it. * lib/Automake/Options.pm (_process_option_list): Recognize it. * automake.in (handle_dist): Set FILENAME_FILTER. * lib/am/distdir.am (distdir) [FILENAME_FILTER]: Diagnose long filenames. * tests/fn99.test: New file. * tests/Makefile.am (TESTS): Add fn99.test.