Various tests have been updated to work around issues found with
shell utilities that come with busybox etc.
* dd/test-with-busybox:
t5703: feed raw data into test-tool unpack-sideband
t4124: tweak test so that non-compliant diff(1) can also be used
t7063: drop non-POSIX argument "-ls" from find(1)
t5616: use rev-parse instead to get HEAD's object_id
t5003: skip conversion test if unzip -a is unavailable
t5003: drop the subshell in test_lazy_prereq
test-lib-functions: test_cmp: eval $GIT_TEST_CMP
t4061: use POSIX compliant regex(7)