lv2 rework, sams ffmpeg icons, elision patch
batchrender asset path fix, ru xlat, fixup hevc/h265 opts, expand new bg pngs
remove whitespace at eol
change thread join strategy, fix a few leaks, fix a few bugs
merge: mask fixes/upgrades, overlay plugin rework, popup menu tweak
Merge CV, ver=5.1; ops/methods from HV, and interface from CV where possible