docs(angular.equals): fix simple typo

- JavasScript -> Javascript

Closes #4323
fix(ngTouch): add $event to ng-swipe

Existing documentation implies that an Event object should be available
as `$event` on swipe directives, which previously was only working for
`ng-click`.

Closes #4071
Closes #4321
docs(cookbook/adv_forms): simplify example

Pass the `$index` directly to the `removeContact` function, instead of
searching for it in an expensive forEach loop.

Closes #4320