Add more window globals and shims in task shell

This allows jQuery to be successfully loaded from a web worker
since it does not have a document or window object by default.

Previously it would log about missing methods and properties.

Closes #228

spec/fixtures/jquery-task-handler.coffee

@@ -0,0 +1,4 @@
+module.exports =
+  load: ->
+    $ = require 'jquery'
+    callTaskMethod('loaded', $?)

spec/stdlib/task-shell-spec.coffee

@@ -0,0 +1,23 @@
+Task = require 'task'
+
+describe "Task shell", ->
+  describe "populating the window with fake properties", ->
+    describe "when jQuery is loaded in a web worker", ->
+      it "doesn't log to the console", ->
+        spyOn(console, 'log')
+        spyOn(console, 'error')
+        spyOn(console, 'warn')
+        class JQueryTask extends Task
+          constructor: -> super('fixtures/jquery-task-handler.coffee')
+          started: -> @callWorkerMethod('load')
+          loaded: (@jqueryLoaded) ->
+
+        task = new JQueryTask()
+        task.start()
+        waitsFor "web worker to start and jquery to be required", 5000, ->
+          task.jqueryLoaded
+        runs ->
+          expect(task.jqueryLoaded).toBeTruthy()
+          expect(console.log).not.toHaveBeenCalled()
+          expect(console.error).not.toHaveBeenCalled()
+          expect(console.warn).not.toHaveBeenCalled()