- oakcodec: de-Qt all 20 sources (QThread decode loop -> std::thread,
QObject/signals -> callbacks), pure C ABI in include/codec with
refcounted neutral handles (OakFrame/OakDecoder/OakEncoder),
framemanager moved in from render, frame_to_buffer/buffer_to_frame
moved in from oakcommon oiioutils, codec->task via submit callback
(M8 will register), all cross-module calls go through the other
side's C API, -fvisibility=hidden + OAKCODEC_API
- oakcommon: handles become refcounted value structs
{ctx, addref, release, abi_version} (FFmpeg-style), pass-by-value
signatures, free() as release wrapper; init_from_native/get_native
for copyable value objects; OakCommonXxx renamed to OakXxx
- oakcommon: add logging (log_debug/info/warning/critical with level
filtering and sink injection) + printf-style oakcommon_log C wrapper
- oakrender: add CancelAtom C API family; complete
oakrender_color_processor_convert_frame; fix get_processor() missing
definition and OCIO env var lookup
- tests: oakcommon 174, oaknode 96, oakrender 42, oakcodec 18, all
green in their standalone builds
