Merge remote-tracking branch 'remotes/berrange/tags/pull-build-2017-11-07-1' into...

Merge build 2017/11/07 v1

# gpg: Signature made Tue 07 Nov 2017 10:14:49 GMT
# gpg:                using RSA key 0xBE86EBB415104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>"
# Primary key fingerprint: DAF3 A6FD B26B 6291 2D0E  8E3F BE86 EBB4 1510 4FDF

* remotes/berrange/tags/pull-build-2017-11-07-1:
  build: remove use of MAKELEVEL optimization in submodule handling
  build: delay check for empty git submodule list
  build: don't fail if given a git submodule which does not exist
  build: allow automatic git submodule updates to be disabled
  build: don't create temporary files in source dir
  build: allow setting a custom GIT binary for transparent proxying

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