This is a tiny patch to glib.h

Description:
* Defined NULL as 0 when compiling C++ code to avoid the following warning:
  "ANSI C++ forbids implicit conversion from `void *' in initialization"

(I don't want to include cstdio just to remove this one :)

11-Mar-99, David Le Corfec <lecorfec@etudiant.univ-mlv.fr>