autotools: add support for disabling MBROLA (--without-mbrola/--with-mbrola=no)

Makefile.am

 	src/compiledict.cpp \
 	src/dictionary.cpp \
 	src/intonation.cpp \
-	src/mbrowrap.cpp \
 	src/numbers.cpp \
 	src/readclause.cpp \
 	src/phonemelist.cpp \
 common_SOURCE += src/klatt.cpp
 endif
 
+if OPT_MBROLA
+common_FLAGS  += -DINCLUDE_MBROLA
+common_SOURCE += src/mbrowrap.cpp
+endif
+
 if AUDIO_RUNTIME
 wave_SOURCE = src/wave.cpp src/wave_pulse.cpp
 wave_LIBS   = -lpulse -lpulse-simple -lportaudio

configure.ac

 	have_klatt=yes
 fi
 
-AM_CONDITIONAL(OPT_KLATT, [test x"$have_klatt" = xyes])
+AC_ARG_WITH([mbrola],
+    [AS_HELP_STRING([--with-mbrola], [enable the MBROLA speech synthesizer @<:@default=yes@:>@])],
+    [])
+
+if test "$with_mbrola" = "no" ; then
+	have_mbrola=no
+else
+	have_mbrola=yes
+fi
+
+AM_CONDITIONAL(OPT_KLATT,  [test x"$have_klatt"  = xyes])
+AM_CONDITIONAL(OPT_MBROLA, [test x"$have_mbrola" = xyes])
 
 dnl ================================================================
 dnl wxWidgets checks.
 	audio configuration:           ${AUDIO}
 
 	Klatt:                         ${have_klatt}
+	MBROLA:                        ${have_mbrola}
 ])

src/mbrowrap.cpp

  * providing a subset of the API from the Windows mbrola DLL.
  *
  * Copyright (C) 2010 by Nicolas Pitre <[email protected]>
+ * Copyright (C) 2013 Reece H. Dunn
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  */
 
 #include "speech.h"
-#ifdef INCLUDE_MBROLA
 
 #include <stdarg.h>
 #include <stdio.h>
 {
 	mbr_errorbuf[0] = 0;
 }
-
-#endif  // INCLUDE_MBROLA

src/speech.h

 #include <sys/types.h>
 
 // conditional compilation options
-#define INCLUDE_MBROLA
 #define INCLUDE_SONIC
 
 #if defined(BYTE_ORDER) && BYTE_ORDER == BIG_ENDIAN