feat(schedule): add user (un)favorite session management



![capture decran 2013-10-21 a 21 58 49](https://f.cloud.github.com/assets/1169286/1375973/c8a8327a-3a8b-11e3-855b-f779a0b2737a.png)
![capture decran 2013-10-21 a 21 58 34](https://f.cloud.github.com/assets/1169286/1375974/c8a9a0b0-3a8b-11e3-8040-d09a8f282848.png)