The Backbone.Router class did not previously extend Events in the
definition file. This caused the TypeScript compiler to raise an
error when calling one of the Events methods (such as on()) on an
instance of a router.
This change allows instances of classes derived from Backbone.Router
to call methods on the Events class that are inherited by the router.
This enables each definition to have a readme if necessary.
Also a .json metadata file to help with package managers.
And last, to have different versions of the definitions.
