[webstorage] storage event should be dispatched async

[Anne van Kesteren]

The storage event currently seems to be dispatched synchronously. Together  
with the storage mutex this easily creates a deadlock:

  Window A (origin x):
  localStorage.x = "foo"

  Window B (origin x):

  onstorage = function(e) { print(localStorage.x) }

We think it should be dispatched asynchronously therefore.


--
Anne van Kesteren
http://annevankesteren.nl/