GDir as DIR replacement - patch

[Tor Lillqvist <tml iki fi>]

Hans Breuer writes:
 > If the following patch is acceptable I would obviously 
 > volunteer to write inline docs, a test app and remove all 
 > the DIR occurences from 'downstream' libs and apps ported 
 > to win32.

I'm for putting this (or something very close) in GLib, except maybe
the g_dir_len() function, I am not sure about the usefulness of
that. Should the functions be made MT-safe?

--tml