minor cleanup

* startup message from UM autoplaylist
* zeroCrossingCount added to sound simulation
* debug messages cleanup

usermods/usermod_v2_auto_playlist/usermod_v2_auto_playlist.h

@@ -85,7 +85,8 @@ class AutoPlaylistUsermod : public Usermod {
     // gets called once at boot. Do all initialization that doesn't depend on
     // network here
     void setup() {
-      USER_PRINTLN("AutoPlaylistUsermod");
+      USER_PRINT(F("AutoPlaylistUsermod startup; enabled = "));
+      USER_PRINT(enabled ? F("true"):F("false")); USER_PRINTLN(F("."));
       initDone = true;
     }