use freetype with ffmpeg build
enable zoom playback filter
zoom: use neighbor scale and larger default size
QCTools.pro: a fix for building on Mac
zoom: center zoom
zoom: sane zoom limit
add Saturation Highlight playback filter
sat highlight: add field split
playback: simply field split process
update changelog
vectorscope: drop chroma subsampling for field split vectorscope

fixes https://github.com/bavc/qctools/issues/59
list: clean up sampling rate
list: better DAR precision
list: add bit rate