docs(guide/ie): add info about what IE versions are supported

Added text from https://github.com/angular/angular.js/issues/4974

Closes #5070
docs(faq): update compressed and minified file size

Closes #5058
docs(guide/unit-testing): minor style and grammar changes

Closes #5057
Merge branch 'master' of https://github.com/angular/angular.js