Gui 436 Display the name of the image on the instance tiles from the landing page

I would not introduce new image caching code into 4.1. The memcached branch uses a different cache library and this will need to be re-factored. If this part of the code is slow because it isn't pulling from the image cache in images.py, please open another ticket for that issue so we can address that separately. I'd much rather see common code be used instead of this which is (more or less) a copy/paste from images.py