Port tests to POSIX.1-2001 grep and later

Port tests to POSIX.1-2001 grep and later

Stop assuming egrep and fgrep in tests.  POSIX.1-2001 removed the
requirement to support egrep and fgrep, and in GNU grep 3.8 and
later, ‘egrep’ warns that is is obsolete, messing up the output of
a test script.
* tests/torture.at:
(Package requiring autopoint (AM_GNU_GETTEXT + _VERSION))
(autoreconf --exclude (autopoint)):
Increase gettext version from 0.11.4 (2002) to 0.13 (2003);
this is the first gettext version that did not require the
existence of egrep.