Modified cache to use a namespace mechanism, which is what I need, based...

This may not at all be anything that you are interested in, as I more than likely have a particular use-case, but maybe you will find a few new methods that I added to be useful, as well as marginally improved doc strings. I will try to clean-up doc strings more, but for the moment this is all I can offer, sorry. Hope you find some value in something here.