Minor code style improvements (mostly whitespace)

static/main.js

@@ -81,7 +81,6 @@ function addKeyListeners() {
 		}
 	};
 
-
 	// keyboard listener for playing sounds using enter key
 	var buttons = document.querySelectorAll(".sound");
 
@@ -181,7 +180,7 @@ function playSound(filename) {
 }
 
 function killAllHowlerAudio() {
-	for(i=0; i<howlerSounds.length; i++) {
+	for (var i = 0; i < howlerSounds.length; i++) {
 		howlerSounds[i].stop();
 	}
 }