feat(scenario): expose jQuery for usage outside of angular scenario

The global jQuery reference is removed by angular scenario and only a local scoped reference is kept. To make jQuery available for other code, a new reference angular.scenario.jQuery is added.
fix(re-bootstrap): Throw an error when bootstrapping a bootstrapped element.

Nothing would prevent a user from accidentally calling angular.bootstrap on an element that had already been bootstrapped. If this was done, odd behavior could manifest in an application, causing different scopes to update the same DOM, and causing debugger confusion.

This fix adds a check inside of angular.bootstrap to check if the passed-in element already contains a class of ng-scope, and if so, will throw an error.