Merge remote-tracking branch 'remotes/stsquad/tags/pull-testing-and-tcg-121119-1...

Testing and plugins for rc1

  - add plugin API versioning
  - tests/vm add netbsd autoinstall
  - disable ipmi-bt-test for non-Linux
  - single-thread make check

# gpg: Signature made Tue 12 Nov 2019 14:34:30 GMT
# gpg:                using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* remotes/stsquad/tags/pull-testing-and-tcg-121119-1:
  tcg plugins: expose an API version concept
  .travis.yml: don't run make check with multiple jobs
  tests/vm: support sites with sha512 checksums
  tests: only run ipmi-bt-test if CONFIG_LINUX
  tests/vm: update netbsd to version 8.1
  tests/vm: use console_consume for netbsd
  tests/vm: add console_consume helper
  tests/vm: netbsd autoinstall, using serial console

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>