Merge branch 'dd/test-with-busybox'

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)

diff --cc t/t5616-partial-clone.sh
Simple merge

diff --cc t/test-lib-functions.sh
Simple merge