In preparation for testing several different whitespace
options, let's split out the setup and cleanup steps of the
whitespace test.
While we're here, let's also switch to using "<<-" to indent
our here-documents properly, and use q_to_tab to more
explicitly mark where we expect whitespace to appear.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>