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 not used by any of the espeak-ng voices and languages.
Additionally, this functionality would be superceded by support
for specifying the language used by different scripts in the
language argument on the command line.

reduced length to 160 for unstressed syllables

Added some exceptions to the italian dictionaries

1.  Store the encoding enumeration values in the Translation
    object, instead of the charset table.

2.  Use the encoding.c charset table data instead of the ones
    in translate.c.

3.  Remove the charset language file option -- it is only used
    in the Arabic language file, but is used incorrectly there.

4.  Specify ISO 8859-6 for the 8-bit encoding for Arabic instead
    of UTF-8, so that espeakCHARS_8BIT and espeakCHARS_AUTO work
    correctly for Arabic.

IT: Unstressed final syllable is diminished

IT: Preserve unstressed monosyllable words and allow secondary stress in multisillable words indicated as unstressed in it_list.

Moved include/espeak/speak_lib.h to include/espeak-ng/speak_lib.h and
created a symlink from the original location.

Replace upercase O in ditc source

Added statements for unstressed vowels, change length/amplitude for unstressed vowels.

improved spanish prosody in tr_language.c

Added rule for suffix mente in es_rules

Translated language names

Added rules for letter spanish ce cedilla, see issue 130

Intonation: improved head and prehead in tune q6

Fixed length stressed vowels in tr_language.c (see #80).

Improved phonemes, new statements for [a] and long close [o].

Added last improvements in italian dict source tested on april-may 2016.

This commit has been reported to cause distortions in phoneme
pitches and speeds.

Also use size_t instead of int in some places
where it make sense