FS-7519: increase default video buffer to 2mb in avformat and add vbuf file param to change it per file using a number of bytes with k or m modifier for kilobytes and megabytes

use the magick-core API
We have pdfs and gifs
auto play gif and png
yeah, you can play video files with imgk

video only
requires ffmpeg binary
need autoplay=(1000/FPS)

move nested condition parsing to only happen if main condition was satisfied may alter behaviour see docs and FS-4935

FS-7513: add auto-3d-position attr to <layout> and the auto as a valid value in existingaudio-position in <image>  to auto-arrage the 3d openal positioning to either set it for the whole layout or an individual image

FS-7513: add profile param video-no-video-avatar and variable video_avatar_png to set video replacement avatar images
add also video_no_video_avatar_png to only check the var on no-video situations