Converts additional nested panels to subsections

Related to https://github.com/sonatype/nexus-pro/pull/431

Before:
![](https://s3.amazonaws.com/uploads.hipchat.com/18157/91677/QINlo6fcGo466N9/2014-10-24_1325.png)

After:
![screen shot 2014-10-24 at 4 46 20 pm](https://cloud.githubusercontent.com/assets/186715/4777856/fa595178-5bd7-11e4-8d39-54a9b1669688.png)