Refactor the transport options parsing so that protocols that aren't
directly smart transports (file://, git://, ssh:// & co) can record
the smart transport options for the case if it turns that transport
can actually be smart.
Signed-off-by: Ilari Liusvaara <ilari.liusvaara@elisanet.fi> Signed-off-by: Junio C Hamano <gitster@pobox.com>