Support Tenant-Skinnable Touch Icons

Because the OAE doesn't currently have any touch icons defined, the home screen icon isn't a very good one.

![screen shot 2014-03-28 at 9 18 42 am](https://cloud.githubusercontent.com/assets/1731910/2549849/efefab94-b67b-11e3-8e8a-44e2f9ae87ea.png)

Seems like this would also need to be tenant-skinnable