lwlibav: Fix parsing H.264 stream in some file formats.

This is a regression in c536077e91.
lwlibav: Fix seeking around last frames.

This is a regression in 458cb1aa04.
lwlibav: Fix listing extradata of H.264 stream in some file formats.
lwlibav: More robust check if converting 14496-15 format into H.264 byte stream format is needed.
lwlibav: Don't split extradata from pkt->data of H.264 stream without start codes.
lsmashinput: Fix chroma linesize for SSSE3 version of func convert_yv12i_to_yuy2.
lwlibav: Always treat repeat_pict as field level.
lwlibav: Support repeat flags.

Original patch by Masaki Tanaka <maki.rxrz@gmail.com>.
lsmashdumper: Forgot to change the information of filter plugin.
lsmashmuxer: Forgot to change the information of filter plugin.
vslsmas: Add 'dominance' option to specify field dominance.

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2: Bottom -> Top
lsmashsource: Add 'dominance' option to specify field dominance.

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lwlibav: Avoid copying field data from the same frame buffer twice.