RDF viewer at /xmlui/data to get a context-path to load static resources

It seems that /xmlui/data has a hardcoded assumption that you are deploying xmlui to the ROOT context. So, I've added some code to the XSL to get it to try to figure it out. Tested on my localhost thus far.

Can't load static resources (before this commit)
![screen shot 2014-10-07 at 5 12 28 pm](https://cloud.githubusercontent.com/assets/58014/4550856/c96782bc-4e6a-11e4-8519-adeb7c908d0a.png)

Can load static resources (after this commit)
![screen shot 2014-10-07 at 5 12 55 pm](https://cloud.githubusercontent.com/assets/58014/4550862/db2a7c66-4e6a-11e4-8cbd-38c64a2104cc.png)