libx264 now returns NAL units instead of raw data.  x264_nal_encode is no longer a public function.
See x264.h for full documentation of changes.
New parameter: b_annexb, on by default.  If disabled, startcodes are replaced by sizes as in mp4.
x264's VBV now works on a NAL level, taking into account escape codes.
VBV will also take into account the bit cost of SPS/PPS, but only if b_repeat_headers is set.
Add an overhead tracking system to VBV to better predict the constant overhead of frames (headers, NALU overhead, etc).