Tentative built-in "git show"

This uses the "--no-walk" flag that I never actually implemented (but I'm
sure I mentioned it) to make "git show" be essentially the same thing as
"git whatchanged --no-walk".

It just refuses to add more interesting parents to the revision walking
history, so you don't actually get any history, you just get the commit
you asked for.

I was going to add "--no-walk" as a real argument flag to git-rev-list
too, but I'm not sure anybody actually needs it. Although it might be
useful for porcelain, so I left the door open.

[jc: ported to the unified option structure by Linus]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/revision.h b/revision.h
index 6eaa904..7b85486 100644
--- a/revision.h
+++ b/revision.h
@@ -26,6 +26,7 @@
 	/* Traversal flags */
 	unsigned int	dense:1,
 			no_merges:1,
+			no_walk:1,
 			remove_empty_trees:1,
 			lifo:1,
 			topo_order:1,