libpipi: include <stdlib.h> in files where NULL is used.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2911 92316355-f0b4-4df1-b90c-862c8a59935f

pipi/combine/mean.c

@@ -18,6 +18,8 @@
 
 #include "config.h"
 
+#include <stdlib.h>
+
 #include "pipi.h"
 #include "pipi_internals.h"
 

pipi/combine/minmax.c

@@ -18,6 +18,8 @@
 
 #include "config.h"
 
+#include <stdlib.h>
+
 #include "pipi.h"
 #include "pipi_internals.h"
 

pipi/combine/mulscreen.c

@@ -18,6 +18,8 @@
 
 #include "config.h"
 
+#include <stdlib.h>
+
 #include "pipi.h"
 #include "pipi_internals.h"
 

pipi/combine/rgb.c

@@ -18,6 +18,8 @@
 
 #include "config.h"
 
+#include <stdlib.h>
+
 #include "pipi.h"
 #include "pipi_internals.h"
 

pipi/combine/subadd.c

@@ -18,6 +18,7 @@
 
 #include "config.h"
 
+#include <stdlib.h>
 #include <math.h>
 
 #include "pipi.h"