make embargo template theme-able -- Stanford Branch

Use "Stanford-style" theming to enable you to put your own embargo notice up.

I will submit this same change in a separate PR to master.  The change to the Stanford theme has already been committed to master there.  

@caesar2164 -- can you review please?

![screen shot 2014-03-05 at 3 09 43 pm](https://f.cloud.github.com/assets/621565/2340050/64115de0-a4bd-11e3-8e12-95e230867842.png)