Merge remote-tracking branch 'remotes/kraxel/tags/pull-usb-20141028-1' into staging

Fixes for libcacard (usb smartcard emulation), xhci and uhci.

# gpg: Signature made Tue 28 Oct 2014 10:39:52 GMT using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-usb-20141028-1:
  uhci: remove useless DEBUG
  xhci: add property to turn on/off streams support
  libcacard: don't free sign buffer while sign op is pending
  libcacard: Lock NSS cert db when selecting an applet on an emulated card
  libcacard: introduce new vcard_emul_logout

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