Feature/dependency management

@vecna @evilaliv3 read this carefully as it will affect your development life on GLClient.

In particular pay attention to https://github.com/globaleaks/GLClient/commit/427238d1b82ccce699936765e7e8ce92d5aaca36.

```
Move dependency management over to bower.

DEVELOPERS OF GLCLIENT BEWARE:
This means that from now on you will have to initialise the dependencies of
GLClient by running:

    bower update

```