git-cvsserver runs hooks/post-update

Although we have introduced post-receive, we have not deprecated post-update
hook.  This adds support for it to emulate receive-pack better.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-cvsserver.perl

@@ -1357,6 +1357,12 @@ sub req_ci
 		close $pipe || die "bad pipe: $! $?";
 	}
 
+	### Then hooks/post-update
+	$hook = $ENV{GIT_DIR}.'hooks/post-update';
+	if (-x $hook) {
+		system($hook, "refs/heads/$state->{module}");
+	}
+
     $updater->update();
 
     # foreach file specified on the command line ...