Game Browser Improvements

[torlenor]

Game Browser should resemble the looks of the Twitch.tv homepage, which means especially showing the game icons and if one browses a game, the streamer previews.

Additional features:

• It should be possible to follow/bookmark a channel directly from the Game Browser window.
• In addition a nice feature would be, to add a game as tab in the MainWindow (besides the tabs for Following and Bookmarks).