lavfi/overlay: fix debug PTS output in try_filter_frame()

The PTS of the input frames must be interpreted according to the input
timebase, which is not the same as the output timebase.
lavu/samplefmt: add av_samples_alloc_array_and_pointers()
examples/resampling_audio: make use of av_samples_alloc_array_and_samples()

Simplify.
cmdutils_common_opts: fix loglevel help text as its inaccurate

ffmpeg and ffplay use the loglevel as well as libpostproc, libswscale
and libswresample.

Also this makes the text shorter

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
cmdutils: allow forcing log line repeation

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