[MIE-1470] Routing and FilterManager modules

Added 2 modules:

### FilterModule 
Allows us to set filters  that can be used:
   * When querying the service to get activities. When building the url to ask the service for activities, the url might have some variables and the FiltersModule can provide values to it.
   * When receiving new activities from sockets. FiltersModule has a 'matchActivity' method which checks if the received activity must be appended to the list of activities.

So now, when instanciating the service you can do this:


```
                config = {
                    activityStreamServiceAPI: 'http://as.dev.nationalgeographic.com:9365/',
                    filters: {actor: 'db_user/1' ,'verb': 'FAVORITED', object: 'blog_article'}
                    user: {
                        type: 'db_user',
                        id: 1
                    }
                };
                AS.ready(config)
```
Will filter by actor where actor_type='db_user' and aid=1, verb is 'FAVORITED' and 'object_type' is 'blog_article'. So filter values can have the format 'type' or  'type/aid'.


### Routing Module.
Has 2 main methods:
   *  'urlForContext' method which allows us to get the most specific url for a given set of filters. 
   * 'get' which allows us to get the url for a given route name and a context.
   

Unit tests provided
Hmm maybe not.. I see why the context looks like `actor_type` instead of `{actor: {type:...`. It is just a little bit confusing that we are juggling around so many different ways of describing the filter. Match activity looks at one set of properties, setFilter looks at something else, and urlForContext looks at something else still. Please consider adding method signatures to the inline documentation to fully document what the arguments should look like so that these methods are more reusable.