In order to modernize the tests, move commands that currently run
outside of test cases into a test case. Where possible, clean up files
that are produced using test_when_finished() but in the case where files
persist over multiple test cases, create a new test case to perform
cleanup.
Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>