Fixed memory leak reported by Dave Beckett Removed spurious comment

* parser.c, xmlmemory.c, include/libxml/xmlmemory.h: Fixed
  memory leak reported by Dave Beckett
* xmlschemas.c: Removed spurious comment reported on the mailing
  list
* xinclude.c, xpath.c, xpointer.c, libxml/include/xpointer.h:
  Further work on Bug 129967 concerning xpointer range handling
  and range-to function; much better, but still not complete

xmlmemory.c

@@ -811,6 +811,20 @@ xmlInitMemory(void)
      return(0);
 }
 
+/**
+ * xmlCleanupMemory:
+ *
+ * Free up all the memory associated with memorys
+ */
+void
+xmlCleanupMemory(void) {
+    if (xmlMemInitialized == 0)
+        return;
+
+    xmlFreeMutex(xmlMemMutex);
+    xmlMemInitialized = 0;
+}
+
 /**
  * xmlMemSetup:
  * @freeFunc: the free() function to use