Beginning to split test code up by backbone version.
Externs for Backbone 0.9.10
Extern for Collection#slice
Collection.fetch was accidentally overriden.
Some fixes to Model#fetch extern, adding proper Collection#fetch extern
`options` param for Model#fetch is optional.
Fixing bug with call to _.include in collection test
Bugfixes: Collection#off and #unbind were not properly aliased.
Adding proper Collection#groupBy and #sortBy externs
Extern for Collection#update
Add type annotation to events tests to make closure compiler happy.
Since cc doesn't understand semantics of _.extend, tell it explicitly
that all these `obj` variables have all the properties of
Backbone.Events.
Adding externs for Events#listenTo and #stopListening.
Bugfix: extern for Model#save marked optional params as required.
Bugfix: View#setElement can take a string as well as Element/jQuery
Extern for view.options
Adding environment js setup from backbone tests.
Significant update/rewrite of externs for 0.9.10 Backbone.History.
validationError property on Backbone.Model