[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
window.r shouldn't be commited, my bad, I was using it for testing proposes.

About the singleton, I was agree at the 1st glance. But I have 2 reasons why I think it might not be a good idea:
   * If I change that there will be an inconsistency with other modules, like Logger, I'm not comfortable with the idea that some modules return a singleton object an others return a class.  
   * routing is only needed by activityStream.coffee, I don't see why to use it in other modules so far, but I understand this might be wanted in the future. I think the opposite about Logger. I think Logger should really be a Singleton so that we can use it in several modules.

Thoughts?