[dev] Abstract vs. Base

[Chuck Hagenbuch]

Quoting Jan Schneider <jan at horde.org>:

> For abstract base classes, we currently use both (Abstract, and  
> Base) for the class and file names, i.e. Horde_Db_Adapter_Abstract  
> and Horde_Cache_Base.
> We have to agree on one of those, I personally don't have any preference.

I prefer Base. I went back and forth on the Db classes, and eventually  
stayed with Abstract since it matched the Mad code it was based on.  
I'm fine with switching it to Base at this point though.

-chuck