(PR#9802) generic_city_refresh speedup via caching

<URL: http://rt.freeciv.org/Ticket/Display.html?id=9802 >

> [bhudson - Sat Aug 28 22:28:14 2004]:
> 
> > [per - Wed Aug 25 19:39:05 2004]:
> > On Wed, 25 Aug 2004, Jason Short wrote:
> > > > [bhudson - Wed Aug 25 01:26:21 2004]:
> > > Assuming the effects patch gets committed soon, I'd rather wait
> until
> > > that's done (your patch touches some building effects code). But
> if
> > > nothing happens on it soon (~1 week) we should go forward with
> this.
> > > This code is a bit complicated so if there's a way to split it up
> that
> > > would be helpful.
> 
> What would be a good way to split it up?  I can see three things going
> on:
> (1) new struct and field; move the three ints that were cacheing
> things into the new struct.
> (2) new functions for the CM to call.
> (3) more fields in the new struct.
> 
> If you think that's a good breakup, I can produce patches.

Seems reasonable.

jason