rfe: a common caching system

[tbielawa]

So you know, like, each plugin isn't trying to reinvent the wheel every time

[ashcrow]

Good idea. You can copy my FS/Json based cache system from https://github.com/ashcrow/systats/ (https://github.com/ashcrow/systats/blob/master/server.py#L98) if that would work for you.

[kelcecil]

I think that you'll also want to consider the possibility of making timeout until the data is sale configurable as well. I can see cases where you'd want the cache to become stale faster.