Create an espeak-ng version of espeak_Cancel.

src/include/espeak-ng/espeak_ng.h

 ESPEAK_NG_API espeak_ng_STATUS
 espeak_ng_SpeakCharacter(wchar_t character);
 
+ESPEAK_NG_API espeak_ng_STATUS
+espeak_ng_Cancel(void);
+
 ESPEAK_NG_API espeak_ng_STATUS
 espeak_ng_CompileDictionary(const char *dsource,
                             const char *dict_name,

src/libespeak-ng/espeak_api.c

 	return status_to_espeak_error(espeak_ng_SetPunctuationList(punctlist));
 }
 
+ESPEAK_API espeak_ERROR espeak_Cancel(void)
+{
+	return status_to_espeak_error(espeak_ng_Cancel());
+}
+
 ESPEAK_API void espeak_CompileDictionary(const char *path, FILE *log, int flags)
 {
 	espeak_ng_CompileDictionary(path, dictionary_name, log, flags);

src/libespeak-ng/speech.c

 	return GetTranslatedPhonemeString(phonememode);
 }
 
-ESPEAK_API espeak_ERROR espeak_Cancel(void)
+ESPEAK_NG_API espeak_ng_STATUS espeak_ng_Cancel(void)
 {
 #ifdef USE_ASYNC
 	fifo_stop();
 	for (int i = 0; i < N_SPEECH_PARAM; i++)
 		SetParameter(i, saved_parameters[i], 0);
 
-	return EE_OK;
+	return ENS_OK;
 }
 
 ESPEAK_API int espeak_IsPlaying(void)