cmdline: print out list of encoders in --version info

src/encoder_list.h

@@ -20,6 +20,8 @@
 #ifndef MPD_ENCODER_LIST_H
 #define MPD_ENCODER_LIST_H
 
+#include <stdio.h>
+
 struct encoder_plugin;
 
 /**
@@ -32,4 +34,7 @@ struct encoder_plugin;
 const struct encoder_plugin *
 encoder_plugin_get(const char *name);
 
+void
+encoder_plugin_print_all_types(FILE * fp);
+
 #endif