Editor: Clear background and fog.

editor/js/Editor.js

@@ -422,6 +422,8 @@ Editor.prototype = {
 		this.storage.clear();
 
 		this.camera.copy( this.DEFAULT_CAMERA );
+		this.scene.background.setHex( 0xaaaaaa );
+		this.scene.fog = null;
 
 		var objects = this.scene.children;
 

editor/js/Sidebar.Scene.js

@@ -237,6 +237,8 @@ Sidebar.Scene = function ( editor ) {
 
 	// events
 
+	signals.editorCleared.add( refreshUI );
+
 	signals.sceneGraphChanged.add( refreshUI );
 
 	signals.objectChanged.add( function ( object ) {