gvt-next-2017-02-24

- Min's vGPU failsafe to guard against non-secured guest
- Some guest warning fix and host error message cleanup
- Fixed vGPU type refinement for usability issue
- environ string fix from Takashi Iwai
- one kernel oops fix from Chuanxiao
- other misc fixes
Signed-off-by: Jani Nikula <jani.nikula@intel.com>