replaced malloc.h with stdlib.h to quiet compiler

SAX.c

@@ -3,7 +3,7 @@
  */
 
 #include <stdio.h>
-#include <malloc.h>
+#include <stdlib.h>
 #include "tree.h"
 #include "parser.h"
 #include "error.h"

entities.c

@@ -7,7 +7,7 @@
  */
 
 #include <stdio.h>
-#include <malloc.h>
+#include <stdlib.h>
 #include <string.h>
 #include "entities.h"
 

parser.c

@@ -15,7 +15,7 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <string.h> /* for memset() only */
-#include <malloc.h>
+#include <stdlib.h>
 #include <sys/stat.h>
 #ifdef HAVE_FCNTL_H
 #include <fcntl.h>

tester.c

@@ -24,7 +24,7 @@
 #endif
 #include <stdio.h>
 #include <string.h>
-#include <malloc.h>
+#include <stdlib.h>
 
 #include "parser.h"
 #include "tree.h"

tree.c

@@ -11,7 +11,7 @@
 #include "config.h"
 #include <stdio.h>
 #include <ctype.h>
-#include <malloc.h>
+#include <stdlib.h>
 #include <string.h> /* for memset() only ! */
 
 #ifdef HAVE_ZLIB_H