Use AS_HELP_STRING in AM_SILENT_RULES. * m4/silent.m4 (AM_SILENT_RULES): Use `AS_HELP_STRING' to format help message regarding configure options `--enable-silent-rules' and `--disable-silent-rules'. Also throw in a couple of cosmetic changes in the related `case' statement (indentation, balancing of parentheses). * THANKS: Update. From a report by Jeff A. Daily.