Added initial "server" part.

[kafeijao]

• Added some initial API code for HTTP and WS.
• Added fetching the image urls for the friends thumbnails.
• Added image caching on the AppData folder of the app. Todo: Create cache manager to keep the size in check
• Exposed two events to the front-end to be able to listen for friend state updates, and another for when image load
• Created an example on how to consume the said events on client/frontend.js