Fix a bug where ChannelFuture.setFailure(null) doesn't fail

Motivation:

We forgot to do a null check on the cause parameter of
ChannelFuture.setFailure(cause)

Modifications:

Add a null check

Result:

Fixed issue: #2728
Implemented LZ4 compression codec

Motivation:

LZ4 compression codec provides sending and receiving data encoded by very fast LZ4 algorithm.

Modifications:

- Added `lz4` library which implements LZ4 algorithm.
- Implemented Lz4FramedEncoder which extends MessageToByteEncoder and provides compression of outgoing messages.
- Added tests to verify the Lz4FramedEncoder and how it can compress data for the next uncompression using the original library.
- Implemented Lz4FramedDecoder which extends ByteToMessageDecoder and provides uncompression of incoming messages.
- Added tests to verify the Lz4FramedDecoder and how it can uncompress data after compression using the original library.
- Added integration tests for Lz4FramedEncoder/Decoder.

Result:

Full LZ4 compression codec which can compress/uncompress data using LZ4 algorithm.