split up pandora.js

static/js/pandora/ui/backButton.js

@@ -0,0 +1,16 @@
+// vim: et:ts=4:sw=4:sts=4:ft=js
+pandora.ui.backButton = function() {
+    var that = Ox.Button({
+        title: 'Back to ' + app.config.itemName.plural,
+        width: 96
+    }).css({
+        float: 'left',
+        margin: '4px'
+    })
+    .bindEvent({
+        click: function(event, data) {
+            pandora.URL.set(pandora.Query.toString());
+        }
+    });
+    return that;
+};