doc/libavutil: remove include of opencl.texi

This is inconsistent with the rest of the docs.
doc: merge syntax.texi, eval.texi and opencl.texi into utils.texi
doc/utils: apply misc fixes to OpenCL docs
lavfi/crop: restore pos constant, and fix "t" variable misplacement in variable array

Fix evaluation of expressions containing the t variable.
lavfi/crop: log pos in debug message
lavfi/hue: make do while (0) form meaningful.
lavfi/hue: copy alpha plane too

Signed-off-by: Paul B Mahol <onemda@gmail.com>
ffplay: replace opaque/params for buffersinks

This fixes a regression caused by droping opaque.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avdevice/lavfi: add error checking for av_opt_set_int_list()

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