Better handling of the EventCaller.emit() method for argument passing.

app/js/EventCaller.js

     this.__listeners = {};
   }
 
-  emit(eventName, args=null){
+  emit(){
+    var args = Array.from(arguments);
+    if (args.length <= 0)
+      throw new Error("Missing required eventName argument.");
+    var eventName = args[0];
+    args = args.slice(1);
+
     if (typeof(eventName) !== 'string')
       throw new TypeError("Expected eventName to be string.");
     if (eventName.length <= 0)

app/js/NESPalette.js

         }
       }
     }
-    this.emit("palettes_changed", [{type:"ALL"}]);
+    this.emit("palettes_changed", {type:"ALL"});
     return this;
   }
 
     }
     if (pci == 0){
       this.__BGColor = sci;
-      this.emit("palettes_changed", [{type:"ALL", cindex:0}]); 
+      this.emit("palettes_changed", {type:"ALL", cindex:0}); 
     } else { 
       this.__palette[(p*3) + (pci-1)] = sci;
-      this.emit("palettes_changes", [{type:(p < 4) ? "TILE" : "SPRITE", pindex:p, cindex:pci}]);
+      this.emit("palettes_changes", {type:(p < 4) ? "TILE" : "SPRITE", pindex:p, cindex:pci});
     }
     return this;
   }