Use the new icon in place of [ Wf ] in the howto dialog

It looks like this: 

![icon](http://f.cl.ly/items/390N3J0D1Q1W0a3l1r2R/Screen%20Shot%202013-04-29%20at%205.52.59%20PM.png "icon")

The margin fiddling has to do with the fact that the 2x icon is 29px high while the 1x icon is 15px high, which is something we could ask @larz0 to fix for us.