Add initial support for Pyash languagege, more info:

* https://www.academia.edu/34133204/Pyash_One_Language_to_Unite_Them_All
* https://gitlab.com/liberit/pyac

This reverts commit 6042eb8d1e.

The change causes an issue with `pt-BR` and possibly other languages
and voices.

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.

This reverts commit 0f55204522.

This breaks using voice files like mb-de5-en. It could also use
named values for the stress rules (e.g. 'first-syllable').

Keyword stressRule in voices.c handles setting langopts->stress_rule.

tr_languages.c still contains the setting for some languages that don't have a language file yet.

Contributes to:
Issue #218, https://github.com/espeak-ng/espeak-ng/issues/218

Contributes to:
Issue #218, https://github.com/espeak-ng/espeak-ng/issues/218

Changes:
language files have a new keyword letterVowel. It can be a latin alphabet from a-z or a hex value (used by bulgarian).
Errors in parsing the values are only reported, nothing is done about them.

About testing:
I haven't noticed any differences in the output audio with letterVowel set or unset in any tested language. The code seems to work and the correct bits seem to be set, but I don't know how to confirm from the final audio.

TODO:
1. Write better documentation in docs/voices.md
2. The code uses new_translator. Should it use translator instead?

This is because the emoji are language specific.

Supporting phoneme-based voices in espeak-ng is currently complex,
and has issues that need to be fixed in the core code before
adding support for them.

Creating  the language  variant , swiss french. Primarily for counting
as Swiss French uses huitante  for 80 and ,  like the Belgians septante
eand nonante for  70 and 90.