[Dundi] Caching

[Mark Spencer]

I left caching off my "todo" list earlier.  It's going to be important to 
decide what the best cache time is.  Obviously the longer the cache time, 
the fewer wasted transactions there are, but at the same time, the longer 
it can take for a number relocation to take effect.

Right now the cache is set at 3600 seconds, or one hour.  I think we're 
going to have to revisit this eventually.  Would a cache time of 24 hours 
be unreasonable?  What about caching "hints" for 24 hours and caching 
numbers for less?

Mark