Add support for P2 Resolved Posts plugin

Over on the Ghost company P2 we use a very handy little plugin called [P2 Resolved Posts](http://wordpress.org/plugins/p2-resolved-posts/) - which allows you to mark messages which need to be followed up on later.

Unfortunately this plugin conflicts like a proverbial motherfucker with Houston.

(showing hover state on all 3 posts)

![screen shot 2013-11-01 at 15 08 17](https://f.cloud.github.com/assets/120485/1453942/cd588ce4-42ff-11e3-85cf-547d37c313aa.png)

## PR In Action

This PR adds overrides for the default Resolved Posts styles to match the Houston theme, and fix the display issues. The plugin injects its shit via `<style>` tags - which really sucks - so a !important statements were necessary to get past the defaults.

We also hook into the fontawesome icon font to provide a slightly more pleasing default state for a normal post which needs a "flag as unresolved" CTA.

![screen shot 2013-11-01 at 15 10 09](https://f.cloud.github.com/assets/120485/1453964/2d4852ec-4300-11e3-9888-05ab8010a436.png)

## Other Issues

Houston's styles totally fuck the Unresolved Posts status hover menu thing. So this fixes that, too.

![screen shot 2013-11-01 at 15 09 16](https://f.cloud.github.com/assets/120485/1453945/d0983332-42ff-11e3-8ac8-f832ea52b1f0.png)

![screen](https://f.cloud.github.com/assets/120485/1453974/5b4d0642-4300-11e3-8a96-732bb73df588.png)