Add support for combined wave strength arguments. (#59)

Add support for swtiching combined waves from command line

doc/en/sidplayfp.pod

@@ -199,6 +199,12 @@ Ranges from 0.0 (light) to 1.0 (dark), the default
 value is 0.5.  If set to auto it will choose a
 predefined value for 6581 depending on the tune author.
 
+=item B<-cw>I<< <w|a|s> >>
+
+Set the strength (width) of combined waveforms.
+'w' for weak (thin) waves, 'a' for average waves,
+and 's' for strong (wide) waves.
+
 =item B<--noaudio>
 
 Run without an audio output device.

src/args.cpp

@@ -413,6 +413,20 @@ int ConsolePlayer::args(int argc, const char *argv[])
                     m_frange = atof(&argv[i][9]);
                 }
             }
+#endif
+#ifdef FEAT_CW_STRENGTH
+            else if (std::strcmp (&argv[i][1], "cww") == 0)
+            {
+                m_combinedWaveformsStrength  = SidConfig::WEAK;
+            }
+            else if (std::strcmp (&argv[i][1], "cwa") == 0)
+            {
+                m_combinedWaveformsStrength  = SidConfig::AVERAGE;
+            }
+            else if (std::strcmp (&argv[i][1], "cws") == 0)
+            {
+                m_combinedWaveformsStrength  = SidConfig::STRONG;
+            }	
 #endif
             // File format conversions
             else if (argv[i][1] == 'w')