New creates a *Session from a plain SSH connection.

AckByteSize is the size in bytes for READ_ACK/WRITE_ACKs.

AckErrMask is the bit mask for error ack ranges.

ChunkSize is the size in bytes for valid read/write requests.

ErrInvalidAck is returned when an ack has any error bits set.

A Session is an SSH-over-WebSocket Relay session.