This adds a useful "Parent:" line to the git commit information window.

It looks something like this (from the infamous octopus merge):

	Author: Junio C Hamano <junkio@cox.net>  2005-05-05 16:16:54
	Committer: Junio C Hamano <junkio@cox.net>  2005-05-05 16:16:54
	Parent: fc54a9c3  (Update git-apply-patch-script ...)
	Parent: 9e30dd7c  (Make git-prune-script executa ...)
	Parent: c4b83e61  (Do not write out new index if ...)
	Parent: 66026590  (diff-cache shows differences  ...)
	Parent: b28858bf  (Update diff engine for symlin ...)

	    Octopus merge of the following five patches.

	      Update git-apply-patch-script for symbolic links.
	      Make git-prune-script executable again.
	      Do not write out new index if nothing has changed.
	      diff-cache shows differences for unmerged paths without --cache.
	      Update diff engine for symlinks stored in the cache.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

where all the parent commit ID's are clickable, because the new lines are
added as part of the "comment" string, and thus the regular clickability
thing will match them automatically.

I think this is good. And my random-tcl-monkey-skills are clearly getting
better (although it's perfectly possible that somebody who actually knows
what he is doing would have done things differently).
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>