[ic] ups_cache expires

[Steve Graham]

> >
> > UPS doesn't change rates that often, and we aren't concerned about
> > the data accumulation.
>
>They do sometimes change fuel surcharges and areas covered by Xarea.
>Also, you would need to closely watch things in early February when
>rates do change.
>
>I think a day is reasonable, actually. It should cut load dramatically
>without problems with wrong rates.
>
>--
>Mike Heins

It's not a big deal to change the source - just trying to make 
minimal changes in order to keep up with future upgrades.

One other thought on ups_cache might be to store the 1st three digits 
of the ship-to zip code in the lookup table - this could save many 
entries from being added, especially if using www lookups on Ground, 
3 day, 2 Day and 1 day, etc.

I know this is not really an issue on 1 day cache expire, but with 
expire set to 30+ days - it will add up.

Thanks for your insight.
Steve Graham