Python queue, 2019-02-22

Python:
* introduce "python" directory with module namespace
* log QEMU launch command line on qemu.QEMUMachine

Acceptance Tests:
* initrd 4GiB+ test
* migration test
* multi vm support in test class
* bump Avocado version and drop "🥑 enable"

# gpg: Signature made Fri 22 Feb 2019 19:37:07 GMT
# gpg:                using RSA key 657E8D33A5F209F3
# gpg: Good signature from "Cleber Rosa <crosa@redhat.com>" [marginal]
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 7ABB 96EB 8B46 B94D 5E0F  E9BB 657E 8D33 A5F2 09F3

* remotes/cleber/tags/python-next-pull-request:
  Acceptance tests: expect boot to extract 2GiB+ initrd with linux-v4.16
  Acceptance tests: use linux-3.6 and set vm memory to 4GiB
  tests.acceptance: adds simple migration test
  tests.acceptance: adds multi vm capability for acceptance tests
  scripts/qemu.py: log QEMU launch command line
  Introduce a Python module structure
  Acceptance tests: drop usage of "🥑

 enable"

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