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`.
I was wondering what a developer that uses Angular 1.3 will think when seeing such a text about 1.2. They may think the docs are obsolete here and currently the situation might be different.

It would be wrong to say sth was introduced in 1.3 when it was added in 1.2 but when we're talking about usage scenarions, 1.3 should IMO fit in the mix. So if we don't want to swap 1.2 for 1.3 here, maybe we should at least note it's about 1.2 *or later*.

What do you think?