* Fixed a bug in the C++ code of SAPI that left the audio buffer full
  between two requests;
* The names of the voices are now provided to the TTS in a case-sensitive
  way (the comparisons in the TTS Registry remain case-insensitive);
* Added some further checks to eSpeak before the registry considers it as a working TTS
  service;
* Removed from the main pom the built of the modules in native-libs/* and
  the built of att-native's tts-adapter;
* Misc minor enhancements.