Buffured TCP listener

[maelhos]

TCP Listener doesn't support buffering multiple requests

When dealing with challenges that require many "small" (meaning much smaller than the maximum buffer input of usually 1024 bytes) requests, we lose a lot of time compared to aggregating multiple requests (if the challenge allows it).

Since the listener receives by chunk, manually unpacking lines is required. In this PR, I suggest a simple modification to the listener to handle aggregated JSON requests. I added a double break to ensure full-exit on the Challenge's first exit set.

Further tests may be required to ensure no exploits can be achieved.

[hyperreality]

Thank you, the changes are now live on CH platform