[Libguestfs] [PATCH nbdkit v2 0/4] tests: Test export flags (eflags).

v1 was here: https://www.redhat.com/archives/libguestfs/2018-December/thread.html#00123 v2: - Document "-" instead of "script=-" and use it in the test; and verify this also works on FreeBSD; and verify that it doesn't depend on the particular behaviour of our wrapper script and should work with installed nbdkit too. - Fix handling of zero flags parameter. - Add "to stdout" for can_fua. - "In future" -> "In the future," in various places. - Make the test work on FreeBSD by avoiding use of endian swaps. - Use socat "cool-write" to avoid occasional EPIPE error seen in tests. - Retest on Linux & FreeBSD. - Extra commit for a small documentation change in nbdkit-sh-plugin. Rich.