jpeg2000dec: parse CDEF

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Conflicts:

	libavcodec/jpeg2000dec.c

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
jpeg2000dec: Support non subsampled 8bit planar pixel formats

Fixes file2.jp2

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>