[PATCH] git-tar-tree: small doc update

document difference in behaviour w/ regard to tree vs.  commit and
correct author information.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Documentation/git-tar-tree.txt

@@ -17,10 +17,17 @@ Creates a tar archive containing the tree structure for the named tree.
 When <base> is specified it is added as a leading path as the files in the
 generated tar archive.
 
+git-tar-tree behaves differently when given a tree ID versus when given
+a commit ID or tag ID.  In the first case the current time is used as
+modification time of each file in the archive.  In the latter case the
+commit time as recorded in the referenced commit object is used instead.
+Additionally the commit ID is stored in a global extended pax header.
+It can be extracted using git-get-tar-commit-id.
+
 
 Author
 ------
-Written by Linus Torvalds <torvalds@osdl.org>
+Written by Rene Scharfe.
 
 Documentation
 --------------