[list] Adds tests of the sort function

Sorts 100 random integers. Reports any out of order and returns an error code.

src/libply/ply-list.c

@@ -363,8 +363,8 @@ main (int    argc,
 
   for (i = 0; i<100; i++)
     {
-      value = malloc(sizeof(int));
-      *value = random() %100;
+      value = malloc (sizeof (int));
+      *value = random() % 100;
       ply_list_append_data (list, (void *) value);
     }