t5700: modernize style
The early part of this test is rather old, and does not
follow our usual style guidelines. In particular:
- the tests liberally chdir, and expect out-of-test "cd"
commands to return them to a sane state
- test commands aren't indented at all
- there are a lot of minor formatting nits, like the
opening quote of the test block on the wrong line,
spaces after ">", etc
This patch fixes the style issues, and uses a few helper
functions, along with subshells and "git -C", to avoid
changing the cwd of the main script.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>