docs(ngClass): distinguish between CSS classes and scope properties

Closes #4914
docs(guide/concepts): controllers can also access scope

Closes #4918
docs(misc/faq): fix invalid escaping of character

Backslash is acting as escape character so text is not properly formatted.

Closes #4923
docs(FormController): remove unnecessary parenthesis

Closes #4936
docs(NgModelController): document `$viewChangeListeners` property

Closes #4948
docs(ngClass): fix e2e test for example

Broken by fd7bca22e16b0ecbe1feaf49bab39d9a44b8df01
docs(tutorial): change controllers to not have name twice

While giving the controller function a name helps with debugging,
since otherwise your controller will be anonymous in stack traces,
passing the name to both the `controller()` method and as the function name
is confusing for beginners.

Closes #4415
Merge branch 'master' of https://github.com/angular/angular.js