Add paper.debug switch, set it to true by default when loading code through load.js and use it to ignore focus / blur events in Event.requestAnimationFrame() during development.

src/load.js

@@ -102,4 +102,12 @@ if (window.tests) {
 for (var i = 0; i < sources.length; i++) {
 	document.write('<script type="text/javascript" src="' + (window.root || '') 
 			+ sources[i] + '"></script>');
+	if (sources[i] == 'src/paper.js') {
+		// Activate paper.debug for code loaded through load.js, as we're in
+		// development mode.
+		document.write('<script type="text/javascript">'
+				+ 'paper.debug = true;'
+				+ '</script>');
+	}
 }
+

src/util/Event.js

@@ -79,6 +79,7 @@ Event.requestAnimationFrame = new function() {
 	var callbacks = [],
 		fastRate = 1000 / 60,
 		slowRate = 1000,
+		focused = true,
 		timer;
 
 	// Installs interval timer that checks all callbacks. This results in much
@@ -103,19 +104,20 @@ Event.requestAnimationFrame = new function() {
 		}, timeout);
 	}
 
-	var focused = true;
-	Event.add(window, {
-		focus: function() {
-			focused = true;
-			// Switch to falst checkCallback calls while window is focused.
-			timer && setTimer(fastRate);
-		},
-		blur: function() {
-			focused = false;
-			// Switch to slow checkCallback calls while window is blured.
-			timer && setTimer(slowRate);
-		}
-	});
+	if (!paper.debug) {
+		Event.add(window, {
+			focus: function() {
+				focused = true;
+				// Switch to falst checkCallback calls while window is focused.
+				timer && setTimer(fastRate);
+			},
+			blur: function() {
+				focused = false;
+				// Switch to slow checkCallback calls while window is blured.
+				timer && setTimer(slowRate);
+			}
+		});
+	}
 
 	return function(callback, element) {
 		if (request)