Updated AngularJS

Added the latest stable AngularJS (1.2.21) as well as the 4 latest beta versions (1.3.0-beta.[14-17]). Files from:
1.2.21: https://code.angularjs.org/1.2.21/
1.3.0-beta.14: https://code.angularjs.org/1.3.0-beta.14/
1.3.0-beta.15: https://code.angularjs.org/1.3.0-beta.15/
1.3.0-beta.16: https://code.angularjs.org/1.3.0-beta.16/
1.3.0-beta.17: https://code.angularjs.org/1.3.0-beta.17/