Be able to call sinsy_ng_getAudioData() more than once

[azimut]

I needed this in order to use this library bindings. I hack it by adding default values on _init and creating a _term. Might be some of this can be upstreamed.

ESPEAK_NG_API espeak_ng_STATUS sinsy_ng_Init(void)
{
  notes = CArrayNew();
  sinsy_notepos = 0;
  sample_pos = 0;
  singing_mode = 1;
  current_sample = SAMPLE_NONE;
  current_sample_length = 0;
  current_syllable = 0;
  preutter = 0;
  voiced = 0;
  return 0;
}

ESPEAK_NG_API espeak_ng_STATUS sinsy_ng_Term(void)
{
  CArrayRemoveAllObjects(notes,1);
  notes = 0;
  singing_mode = 0;
  return 0;
}