There are small differences for diphone sets, but these are not used
from eSpeak NG.

The custom n vowel in ph_english did not specify a lengthmod and
the call to the base n did not set that value.

A new 'hyw' language code has been registered for Western Armenian,
and the arevela and arevmda variant subtags have been deprecated.

This still accepts the hy-arevela and hy-arevmda language tags, but
uses the preferred names for the language files.

E.g. for 'port' this goes through following transformations:

1. written 'port' to phonetic [p'o*@-tS] for eSpeak NG
2. espeak [*] was mapped to MBROLA [r] and [@-] was just skipped
resulting [rt] which is not allowed diphone in br1 voice.

Description of fix:
mapping phonetic [*@-] to [r2] (and skipping [@-]) makes [r2-...] which is
in diphone database. That fixed warnings:

mbrola: Warning: r-t unkown, replaced with _-_
mbrola: Warning: r-d unkown, replaced with _-_
mbrola: Warning: r-n unkown, replaced with _-_
mbrola: Warning: r-m unkown, replaced with _-_
mbrola: Warning: r-s unkown, replaced with _-_

Using make check builds but does not install them.

Using make check builds but does not install them.

Closes #396.