Update Facade class links for correct version

Right now the links on the 4.2 version of http://laravel.com/docs/facades are to the `4.1` version of the API's documentation. This means that links are broken in some cases and information may be outdated. For example, the View facade has an underlying class of `Illuminate\View\Factory` but in 4.1 this was different (` Illuminate\View\Environment` was used instead). This means the API documentation link for the View facade 404s.

This PR fixes the above issues.