* tests/mktests.sh: Use awk rather than grep -E or egrep, to avoid

* tests/mktests.sh: Use awk rather than grep -E or egrep, to avoid
portability problems with regular expressions containing newlines.
(exclude_list, ac_exclude_list, au_exclude_list, ac_exclude_script):
Switch from grep to awk syntax.
(ac_exclude_script): Renamed from ac_exclude_egrep.
(au_exclude_script): Renamed from au_exclude_egrep.