Fix #1282 - "all" callback list is retrieved for each event.
Merge pull request #1283 from braddunbar/retrieve-all

Fix #1282 - "all" callback list is retrieved for each event.
refactor events using array instead of linked-list to improve performance
Avoid throwing when $ is not defined.
Merge pull request #1284 from lifesinger/master

Improve performance using array instead of linked-list to implement Backbone.Events
Tweak events implementation.
Merge pull request #1285 from braddunbar/ajax

Avoid throwing when $ is not defined.
Fix #1292 - unexpected results when passing undefined to Model.hasChanged()

* additional check in hashChanged for when `attr` is present but undefined
* adds tests for expected results when passing undefined
simplifying hasChanged if statement
updating model.previous arguments check to match hasChanged
Refactor _prepareModel.
Merge pull request #1295 from braddunbar/refactor-preparemodel

Refactor _prepareModel.
fixed broken fragment links to underscore proxy methods
adding a rel=canonical
Merge pull request #1293 from wookiehangover/issue1292

Fix #1292 - unexpected results when passing undefined to Model.hasChanged
additional documentation for Model.clear

* specifies that the `id` attribute is removed
documenting model.clear's new behavior in the 0.9.0 changelog
Fix #1310 - off does not skip consecutive events.
adding scrollkit as an example site
Events.off uses reverse iteration to avoid altering indicies.

See comments on 83a24bb2d5355833e5d3184e9d30033db0ca8c74.