BEFORE WE FORK 1.6.x FROM master

[petebacondarwin]

We want https://docs.angularjs.org to reflect the latest full release of Angular. At the moment the docs shown are the current snapshot of master. This requires two things:

• changes to the hosting server to redirect docs.angularjs.org to code.angularjs.org/latest rather than code.angularjs.org/snapshot.
• changes to the release process to additionally copy released files into code.angularjs.org/latest.

[Narretz]

Resolved by #16093