BTTF: Coupon mountain design cleanup

//cc @russellholt @jagtalon @jdorweiler 

I've cleaned up CouponMountain a little more:
- Switched to shorter titles (from the API) for the tiles and I now show the expiry date when present in the detail view (I also strip any wording about expiry from the detail-view heading)
- Made the coupon text a little larger (it was quite small before)
- Added default alphabetical sorting
- Removed the old unneeded detail template

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Before:
![image](https://cloud.githubusercontent.com/assets/873785/2935012/3c27dfc8-d7eb-11e3-9424-bbcc95ae2237.png)

After:
![image](https://cloud.githubusercontent.com/assets/873785/2935010/155d635e-d7eb-11e3-954c-d1d3307bdba8.png)