Add a new option, -W, to show the whole surrounding function of a match.
It uses the same regular expressions as -p and diff to find the beginning
of sections.
Currently it will not display comments in front of a function, but those
that are following one. Despite this shortcoming it is already useful,
e.g. to simply see a more complete applicable context or to extract whole
functions.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>