The default core.excludesfile path is $XDG_CONFIG_HOME/git/ignore.
$HOME/.config/git/ignore is used if XDG_CONFIG_HOME is empty or unset,
as described later in the document.
Signed-off-by: Todd Zullinger <tmz@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>