Changed wrealloc's behaviour to call wfree() and return NULL if the newly

requested size is 0.

WINGs/ChangeLog

@@ -29,6 +29,10 @@ changes since wmaker 0.61.1:
   problem with them: inability to remove handlers next to the called one, from
   the called handler itself. Trying to do this with the old version caused the
   program to crash.
+- changed wrealloc behaviour to be like this: new = wrealloc(old, new_size);
+    1. if old is NULL, return wmalloc(new_size).
+    2. if new_size is 0, call wfree(old), and return NULL.
+    3. if both old is a valid pointer and new_size>0, call realloc.
 
 changes since wmaker 0.61.0:
 ............................