Fix deadlock

Ensure last is a clip even after LoadPlugin() calls

Fix logic for checking frame count in ThunkedInterleave

Allow specifying avisynth DLL

Seems someone uses VideoInfo.image_type to store random flags, so onl…

…y check frame/field related bits on initialization

Fix a race condition

CreateProcess with CREATE_BREAKAWAY_FROM_JOB may fail in some situati…

…ons, just ignore it

new feature: lock threads to cores

inherit block is now available to user