Add desktop notifications, overridable in the same way as other components (although it's not a react component). Also extend the flux dispatcher a little to be less dumb about dispatching while something else is already dispatching.

src/extend.js

@@ -0,0 +1,8 @@
+module.exports = function(dest, src) {
+    for (var i in src) {
+        if (src.hasOwnProperty(i)) {
+            dest[i] = src[i];
+        }
+    }
+    return dest;
+}