Put a "./" at the beginning of all paths given to the merge program so
that filenames beginning with a '-' character don't get interpreted as
options.
This deals with a problem where kdiff3 can be compiled with or without
support for the '--' separator between options and filenames.
Signed-off-by: Patrick Higgins <patrick.higgins@cexp.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>