[resp] use bytearray instead of string

[logger] fix NPE when prepareNewFile returns null in writeOrDrop

[stack] add unit tests for TCP stack

[stack] implement advanced cubic for tcp stack

[poc] standardize SwitchTCP

[test] fix race condition in createMappedByteBufferLoggerWriteOrDrop

[ssl] use nextTick after NEED_TASK to avoid re-entering buffer

[ssl] execute NEED_TASK synchronously, remove resumer indirection

[ssl] enhance ssl wrap rb

[streamed] introduce StreamConnectionStateCallback and StreamedFDHandlerFactory

[xdp] xdp kern bug fix and hex validation upgrade

[vpxdp] sync to new vpxdp version

[sw] pkts might not be initialized after flooding

[chnl] remove duplicated writeOff/writeLen inc/dec

[lib] expose kt version handle(method,url,handler)