Add options to filter the files tab

I think that will be a great option have in the files tab option a filter, or directly don't show 'gifs'.
Maybe the best options would be diferent filters, like Sounds, Images, Media/Ofimatic files, Others...

For the other hand, I think that a tab with all links it's a great impruvement.

I think that the Media Repo Option is not been exploited in Riot. Maybe it's interesting have a room or system tags to clasificate files and a good browser/tab to control this files.