v1.6.8
docs(guide): tweaks to the index and external resources guides
feat($compile): add `strictComponentBindingsEnabled()` method
docs(*): add browserTrigger docs; update references to scenario runner
docs(*): update CONTRIBUTING.md and create DEVELOPERS.md
feat(ngdocs): support popover, foldouts and foldover annotations
docs(tutorial/step_14): replace broken web platform docs link