Merge remote-tracking branch 'remotes/jnsnow/tags/ide-pull-request' into staging

# gpg: Signature made Mon 11 Jan 2016 19:16:27 GMT using RSA key ID AAFC390E
# gpg: Good signature from "John Snow (John Huston) <[email protected]>"

* remotes/jnsnow/tags/ide-pull-request:
  libqos/ahci: organize header
  qtest/ahci: ATAPI data tests
  libqos/ahci: add ahci_exec
  libqos/ahci: allow nondata commands for ahci_io variants
  libqos: allow zero-size allocations
  libqos/ahci: Switch to mutable properties
  libqos/ahci: ATAPI identify
  libqos/ahci: ATAPI support
  ahci-test: fix memory leak
  ide: ahci: reset ncq object to unused on error
  macio: fix overflow in lba to offset conversion for ATAPI devices

Signed-off-by: Peter Maydell <[email protected]>