[packagekit] Caching for APT backend (or how to get queries down to 0.5s)

[Tom Parker]

Richard Hughes wrote:
> Initially looks good (and very compact, well done!).

Thanks!

> Sure. Looks good. If you want you can merge this, as I'm a couple of
> weeks off releasing 0.1.0, although it might be best merged when it
> works.

I'm going to wait until it's up to the level that the existing apt 
backend is at (i.e. pretty much just basic searching), and is capable of 
rebuilding at the right times before I commit. The existing backend can 
at least do those things in a sane way already, even if it is a bit slow.

Tom