Added Spine.app.Helper

Spine.app.Application
 - Moved Spine.app.History::start after run
 - Added requires config item

Spine.app.Controller
 - Added helpers config item
 - Added the ability for route callbacks to reference helpers
 - Added the ability to cancel other routes by returning false from a callback

Spine.app.History
 - Fixed a bug causing the initial hash to not trigger the change event

Spine.app.Router
 - Added the ability to cancel other routes by returning false from a callback

Spine.data.Model
 - Fixed a bug preventing an id from being 0

Spine.dom.Helper
 - Added nested style parsing
 - Added unit injection to styles

Spine.util.Renderable
 - Added the ability for tag to be a string

Spine.view.Box
 - Fixed a typo

Spine.view.binding.Binding
 - Fixed a bug resulting from formatters returning values that were not strings or objects

Spine.view.binding.BindingView
 - Added the ability for a binding to be defined as a function

Spine.view.container.CollectionContainer
 - Added emptyView support

Spine.view.container.Container
 - Added the ability to add items that were already created, not just item configs

Spine.view.layout.Layout
 - Added initContainer
 - Added the ability for wrapperTag to be a string
 - Added wrapperCls config support on items
 - Added wrapperStyle config support on items
 - Added width, height, padding and margin to wrapperStyle if they exist
 - Fixed a bug with items being inserted