When a newer espeak-ng version is released, one should:

- check in debian/rules the LANG_APPROX list that hardcodes the list of voices
for which we have an approximation in espeakup-udeb.restart. If the voice is
released, drop it from both places.

- check in espeakup-udeb.restart the list of mbrola codes against the list in
espeak-ng-data/voices/mb, to add the iso-to-mbrola translation.

When a newer d-i translation is released, one should:

- check if espeak-ng doesn't have support for that voice, but has a voice that
should be approximate enough. Add the language to LANG_APPROX in debian/rules
and the approximation in espeakup-udeb.restart.
