new tabs for Habits and Rewards columns on task page

Goes with https://github.com/HabitRPG/habitrpg-shared/pull/347

This PR adds tabs to the Habits column and the Rewards column:
![screen shot 2014-10-19 at 6 10 46 pm](https://cloud.githubusercontent.com/assets/1495809/4692526/e8f49b68-5768-11e4-91c0-06ae0ddcead0.png)

The "All" tabs show all Habits and all Rewards/Equipment/Skills (i.e., exactly the same as you see currently in your tasks page).

The Habits "Reddish" and "Bluish" tabs split up the Habits based on colour (yellow, orange, red in the "Reddish" tab; green and blue in the "Bluish" tab). I know I would find this useful; not sure about anyone else. Better tab label suggestions are welcome. They must be short otherwise the tabs wrap unpleasantly.
![screen shot 2014-10-19 at 6 24 42 pm](https://cloud.githubusercontent.com/assets/1495809/4692531/71926f4a-5769-11e4-8187-08339132b0d3.png)

The Rewards "Equipment & Skills" tab hides all of the user's custom rewards (useful when you have many rewards but want quick access to the skills).
![screen shot 2014-10-19 at 6 11 34 pm](https://cloud.githubusercontent.com/assets/1495809/4692532/915afe1e-5769-11e4-85e2-2cc4c206089f.png)