Fix showing of path in tree view

Fix showing of path in tree view

This patch fixes two things - links to all path elements except the last
one were broken since gitweb does not like the trailing slash in them, and
the root tree was not reachable from the subdirectory view.

To compensate for the one more slash in the front, the trailing slash is
not there anymore. ;-) I don't care if it stays there though.

Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>