Mute button + RT shows up immediately now in Windows Mixer

see issue 803

rtgui/main.cc

@@ -31,6 +31,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <options.h>
+#include <soundman.h>
 #include "version.h"
 
 #ifndef WIN32
@@ -94,6 +95,8 @@ int main(int argc, char **argv)
 
    Options::load ();
 
+   SoundManager::init();
+
    if (argc>1){
 	   int ret = processLineParams( argc, argv);
 	   if( ret <= 0 )