* depend2.am: Removed erroneous comment. * automake.texi (Program variables): Document nostdinc. (Options): Likewise. * automake.in (get_object_extension): Respect nostdinc option. (handle_options): Recognize nostdinc. * comp-vars.am (DEFS): Use @DEFAULT_INCLUDES@ as sole substitution. * automake.in (read_am_file): Allow conditional includes. Fixes test condincl.test.