* automake.in (handle_dist): Do not define %GETTEXT% if the user is using $seen_gettext_external, this distcheck won't run `./configure' with a meaningless `--with-included-gettext'. * tests/gettext.test: Make sure distcheck uses --with-included-gettext. * tests/gettext2.test: Make sure distcheck does not use --with-included-gettext.