[gnet] compilation problems

[Richard Renard <rick tahoom homeip net>]

while compiling gnet-1.1.7 with garnome-0.18.0 where warnings are 
treated as errors

i found some missing includes

in tests/pack.c
#include <stdlib.h>

in tests/unpack.c
#include <stdlib.h>
#include <string.h>

adding these seems to fix problems

richard.