[patch] Updating "directoryContentsAtPath:"

Howdy!

directoryContentsAtPath: was deprecated in Mac OS X v10.5. So, we need
use contentsOfDirectoryAtPath:error: instead.

This patch remembered myself to say: I'm not changing any pre-existent
behavior. So, if an error wasn't treated, this error still isn't
treated.
Just to clarify, my first effort is to remove all deprecated methods
and not to change any other issue.

Best Regards,

-- 
Fabiano Fidêncio