Begin of a simple UI for the game. Still needs a lot of work

Here we go with a begining of a very simple UI. 
![capture d ecran 2014-12-22 a 10 20 57](https://cloud.githubusercontent.com/assets/3982958/5523099/6085efa0-89c4-11e4-9d78-61b9275aff9c.png)

It still needs more work on mobile UX and brand choices.
At the moment, it's the only way I've found to get a flexbox clean organisation and a working responsive attitude for the video (it needs a container around the player). I'll investigate about this