feat(index.html): update layout to use angular-seed settings

Update to index.html:
- change index.html in line with angular-seed
- update app.scss to use sass-bootstrap
- update controllers.js to add dummy HeaderCtrl (stops errors preventing page loading)
- add directive cloakOnAuth to module.waitForAuth.js
refactor(controllers): move controllers into individual files

- create sepearte files for account, chat, header, home, login controllers
- reformat controllers to pass linting