docs(content): update Angular 1.2 mentions to Angular 1.3

Angular 1.3 docs now describe the process of using this version instead of
the older 1.2 that is the latest stable version.

Also, update jQuery 1.10.x mentions to 2.1.x.

@IgorMinar this is re our latest talk at the AWG meeting. This merge should probably wait until http://docs.angularjs.org is switched to point to the latest commit on the `1.2.x` branch by default instead of `master`.