This patch splits out git-help's functions to builtin-help.c and leaves
only functions used by other builtins in help.c.
First this removes git-help's functions from libgit which are not
interesting for other builtins, second this makes 'git help help' work
again.
Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>