A complete rewrite of the synthesizer
Provide voice gender information to clients.
SSML: add support for the audio element.
Rewrite SAPI support

* Update the code to work with the new version of the synthesizer.
* Implement our own tiny helper library to avoid code duplication when
  implementing COM interfaces.
* Do not store tokens themselves in the registry, but implement
  IEnumSpObjectTokens, so they will be enumerated dynamically, and if
  the user disables a language, it won't be included.
Optimize the question generation script

Optimize generation of phonetic questions as described in the paper
"Feature-Table-Based Automatic Question Generation for Tree-Based
State Tying: A Practical Implementation" by Supphanat Kanokphara and
Julie Carson-Berndsen
SAPI: implement handling of rate, pitch and volume
SAPI: handle reading by characters
Change Russian phoneset

Stressed and unstressed vowels are separate phones again (should we
return to explicitly considering the second degree of reduction too?)
Change the f0 extraction script

* Use Swipe as the third method.
* Add options for setting voicing thresholds for Praat and Swipe.
Fix a typo
Correct the NEWS file

There is SAPI support now, so remove the last paragraph.
Fix pronunciation of numbers
A sentence selection script for recording a speech database in a new language

As there will be no transcriptor at first, we cannot select sentences
by maximizing the diphone coverage. So we implement the same procedure
as Festvox, that is we use letter bigrams.
Database labelling script: add subcommands for different steps of the process.
Retrain Elena with changed labels

As it turnes out, a lot of incorrect pauses have been inserted by the
labeller in places where a word begins with a plosive. Try to remove
them automatically and retrain the voice.
Aleksandr: lower the volume of the voice
A tiny improvement of the sentence selection script

If a phoneme is mostly represented by a particular letter combination,
then maximizing bigram coverage instead of diphone coverage might
produce too few examples. Of cause, it would be better to use phonemic
transcriptions of the sentences, but if we can't, at least treat these
combinations specially, that as as single letters, so we can pick up
more examples of them in different contexts.
Expand escape sequences when parsing ini files
Implement support for so called punctuation mode

For the moment, skip implementation of the tts:style element.
C api: do not ignore RHVoice_message_type_characters