140 grouppositions by points

This PR add the logic to group all the users with same amount of points in the same rank position.

This PR also improves user notifications logic to allow system messages.

Both features in the same screen:
![fwc_rank_m](https://cloud.githubusercontent.com/assets/357127/3397770/4f9c9472-fd25-11e3-906e-bc1d3090bc1f.png)