docs(ngController): global controller fns disabled by default
docs(ngController): global controller fns disabled by default

Update doc to reflect a6e8690676657a952de0d631f16a9a13f67ad8e9,
which disabled use of global controller constructors (by default).

Closes #8466

ggershoni/angular.js,ggershoni/angular.js,ggershoni/angular.js,ggershoni/angular.js