[development] cache API changes

[Gerhard Killesreiter]

Dries Buytaert wrote:
> Hello world,
> 
> I committed Gerhard's cache improvements.  We split up the giant cache 
> table in smaller cache tables:
> 
>   http://drupal.org/node/72290
> 
> As a result, the cache API (cache_get, cache_set, cache_clear_all) 
> changed and contrib modules will have to be updated.

Docs are at http://drupal.org/node/64279#cache-set
cache_clear_all shoudl be renamed, suggestions welcome:
http://drupal.org/node/81461

Cheers,
	Gerhard