Fix #3616 by preventing fold overs for clipped data

Use libsndfile functionality to prevent fold overs when exporting clipped
data. The fold overs occurred when exporting with a bit depth of 24 bit.

src/core/audio/AudioFileWave.cpp

@@ -79,7 +79,12 @@ bool AudioFileWave::startEncoding()
 					outputFile().toUtf8().constData(),
 #endif
 					SFM_WRITE, &m_si );
+
+	// Prevent fold overs when encountering clipped data
+	sf_command(m_sf, SFC_SET_CLIPPING, NULL, SF_TRUE);
+
 	sf_set_string ( m_sf, SF_STR_SOFTWARE, "LMMS" );
+
 	return true;
 }