Made it safe to subscribe and unsubscribe to an event multiple time (with the same listener).
subscribe and unsubscribe are now idempotent
Added ability to subscribe to subscriptions and unsubscriptions.

A publisher can now be notified when someone subscribes to an event. No information about the subscriber is sent to the subscribe-subscriber.
Created a whenContext, which can be used to safely subscribe to events.
This can be used to create a family tree of contexts. A context can destroy the child contexts and unsubscribe any descendant listener
refactored, moved all functions out of createContext method
When the context is destroyed it should no longer be used!
Got rid of EventSubscriber.js, replaced with whenContext
Chrome complains about these headers, so I'm removing them.
See this answer: http://stackoverflow.com/a/7210840/1585

This fixes #20
Made sure the url only contains one ?. Added some other tests

This fixes #13
Lets send the entire config to the PageLoader, so it can use other config options
Added the config option `cachePages`, which either lets the Templates cache pages (when it is true), or tells the PageLoader to add a cachebusting query string to the end of a page url (when it is false).

This fixes issue #12
Merge branch 'notifyOnUnload'
Merge branch 'issue20_removeHeaders'
Merge branch 'issue13_queryString'
Merge branch 'issue12_cachePages'
Added two dev dependencies for grunt, which I forgot a few commits ago.

It would be great if Grunt could resolve these on its own...