Tiny change to add the ID property to every entity

I have searched the code, there is no apparent way to uniquely identify the entity (unless you extract the id from _entityName or i missed something).
Revert to original core.js
Crafty_Core.getId() - Wrapper for entity[0]
Merge pull request #437 from mucaho/patch-2

Tiny change to add the ID property to every entity
fix bug where particles can appear in wrong place

In firefox and chrome (at least), the canvases can wind up not aligned
on the page. This fixes it in my tests. [Thanks Gizmoa.]
Merge pull request #483 from sbyrnes321/particles

fix bug where particles can appear in wrong place
Add resize event and change hitbox on resize

This patch:
* Adds a resize event to "2D" triggered when h or w change
* Allow "Collision" hitboxes to track an entities shape through that event
* Change collision(polygon) to rotate the polygon before attaching it
* Fix some errors in calculating the MBR when a rotated entity was resized
* Adds some tests for resizing rotated objects
Merge pull request #485 from starwed/resize

Add resize event and change hitbox on resize
Refactor DrawManager.draw into separate routines triggered by an event

Instead of directly calling Crafty.DrawManager.draw(), this patch triggers a "RenderScene" event.  draw() is now split between two functions; renderCanvas() and renderDOM().  Using an event instead of a hardcoded function call should make it possible to add new types of rendering.
Create a debug layer

* Add a debug canvas and a base "DebugCanvas" component
* Create several components that build additional functionality on top of the debug canvas
* Add tests and docs
Merge pull request #484 from starwed/debugLayer

Add a rendering layer for debugging
Refactor audio.add, audio.supports

There was a lot of duplicated code when we load audio files; this abstracts that out into a new function audio.create.

It also improves the way we check for supported formats so that it is created if and only if we check for support and we don't have the previous cached result.  This fixes a bug where Crafty.load tried to check for audio file support when that information hadn't been cached.
Implement multiple audio channels

To allow the same sound resource to be played multiple times without resetting, create a bank of audio elements that we use as different "audio channels".  This is pretty basic; there's probably more functionality we could add here.
Handle case where no assets are loading
Fix within and contains methods

These methods test whether the entity is within or contains an entity.  For a rotated entity, we should test against the MBR.  I mentioned this in the docs, and added some tests.

intersect was considering the MBR already; I tweaked the variable names to match within/contains and added to the docs.
Merge pull request #489 from starwed/within-contains

Fix within and contains methods to work on rotated entities
Merge pull request #487 from starwed/audio-add

Refactor Crafty.audio
Fix delay docs
Merge pull request #491 from starwed/DelayName

Fix delay docs
A few small fixes