Adds get/setId methods, stubs getUrl method

* Make id field private, add getter/setter methods to translate
	the Mongo ObjectID to/from a string.
* Stub out a getUrl method, eventually to return the url to the thread.
Removes no longer needed code

* Don't need to do stickit binding inline, handled by mixins
* Removes an unused method binding.
Fixes THreadAPI, adds UserAPI

* ThreadAPI#create sets author & contentHtml properly.
* User model handles json serialization manually, to avoid some hidden methods
	on proxy objects blowing up Jackson serialization
* Adds a UserAPI controller, for now just has a get method for getting a user
	by id
Adds User model, linked to Thread model

* Createa	user model, associated with the thread model in javascript
* updates thread list item template for use with bindings
* Misc bug fixes.