Remove file with prefix 'vaapi' in folder 'common' to crated folder 'vaapi'

1.Create folder 'vaapi' and then create Makefile.am

2.Update Makefile.am, configure.am, common/Makefile.am,
  doc/Makefile.am, encoder/Makefile.am
Merge two log head files in 'codecparsers' and 'common'

1.Merge 'codecparsers/log.h' to 'common/log.h'

2.Remove 'checkVaapistatus' in log.h  to vaapiutils.h

3.Replace 'LOG_INFO' to 'INFO', 'LOG_ERROR' to 'ERROR',
 'LOG_WARNING' to 'WARNING' and 'LOG_DEBUG' to 'DEBUG'
When decode nalu, skip SPS Extension NALs and skip Slice Aux NALs
h264: support process for gaps in frame_num

Follow 8.2.5.2 when frame_num is not equeal to
PreRefFrameNum and is not equal to
(PreRefFrameNum+1)%MaxFrameNum, there would be
"non-existing" picture "used for short-term reference".

Because the driver needs to test the effectiveness
of the picture, dummy picture needs a surfaceID.
And according to the provisions of spec, the dummy
pictures is not used for reference,so surfaceID of
current picture is set to the dummy picture.

Signed-off-by: Zhong Cong <congx.zhong@intel.com>