ref-filter: pass ref_format struct to atom parsers
The callback for parsing each formatting atom gets to see
only the atom struct (which it's filling in) and the text to
be parsed. This doesn't leave any room for it to behave
differently based on context known only to the ref_format.
We can solve this by passing in the surrounding ref_format
to each parser. Note that this makes things slightly awkward
for sort strings, which parse atoms without having a
ref_format. We'll solve that by using a dummy ref_format
with default parameters.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>