Tweak upgrade steps

I took a stab at tweaking the upgrade steps a bit. See:
![screen shot 2014-11-15 at 15 41 52](https://cloud.githubusercontent.com/assets/162976/5056973/2c25023e-6cdf-11e4-99d8-2e00383129aa.png)
![screen shot 2014-11-15 at 15 41 57](https://cloud.githubusercontent.com/assets/162976/5056974/2cea36b2-6cdf-11e4-8fbf-e78ce38702e2.png)

I think `upgrade_summary` or `upgrade_description` is a better name for the partial than `upgrade_short`.