The need for "--" in the git-log synopsis was previously unclear and
confusing. This patch makes it a little clearer.
Thanks to hyy <yiyihu@gmail.com> for his help.
[sp: Changed -- to \-- per prior commit e1ccf53.]
Signed-off-by: martin f. krafft <madduck@madduck.net>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>