Migrate to angular 2

[xi]

Angular 2 has finally been released on 15.9.2016. I could not find any information on the deprecation strategy for angular 1, but it will definitely be deprecated eventually. So we will have to migrate our code.

There is a comprehensive upgrade guide in the docs. It roughly defines the following steps:

1. While still using angular 1, establish conventions that will make upgrading easier.
2. Migrate everything while running both angular 1 and 2 at the same time.
3. Once everything is done, remove angular 1.

One of the most important aspects of (1) seems to be to port existing directives to components. I looked into it and found that we already have a head start with our existing conventions (e.g. always isolate scope) but we will also have to do significant changes.