Convert "skin" to "tool" in various places;  almost entirely within comments,
nothing that will affect code.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@2217 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/memcheck/memcheck.h b/memcheck/memcheck.h
index e817c13..03d7ff9 100644
--- a/memcheck/memcheck.h
+++ b/memcheck/memcheck.h
@@ -82,7 +82,7 @@
       VG_USERREQ__COUNT_LEAKS,
 
       /* These two have been moved into core, because they are useful for
-         any skin that tracks heap blocks.  Hence the suffix.  But they're
+         any tool that tracks heap blocks.  Hence the suffix.  But they're
          still here for backwards compatibility, although Valgrind will
          abort with an explanatory message if you use them. */
       VG_USERREQ__MALLOCLIKE_BLOCK__OLD_DO_NOT_USE,