vebox: fix memory leak of VEBOX state tables.

Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
Following haihao's suggestion, make gen6 phantom slice funcion can be reused by SNB+
Add phantom slice support on IVB+
decoder: h264: fix RefPicList0/1 without frame in DPB.
Add debian files for ppa packaging thx @wsnipex
Bump Changelog to 1.3.3~pre2-1~trusty
Bump version to 1.3.3~pre4-1~trusty