refactor: STCP connections as ETCP links (is_tcp)

- Add is_tcp, tcp_link, tcp_reconnect_* fields to ETCP_LINK
- Remove transport_link from ETCP_CONN, add tcp_link_count
- stcp_link: replace embedded etcp_conn with pointer; add etcp_link backpointer
- stcp_link: link_rx_cb routes ETCP data to etcp_conn_input
- stcp_link: call on_close_cb in close
- New TCP functions: etcp_link_enter_ready_tcp, etcp_tcp_link_start_connect,
  etcp_tcp_link_start_reconnect, tcp_link_close_cb, etcp_tcp_send
- etcp_link_new: handle NULL conn for TCP links; skip enter_init for TCP
- etcp_link_close: close stcp_link for TCP
- etcp_encrypt_send: redirect TCP to etcp_tcp_send (skips AES-CCM)
- tcp_server_on_link: create ETCP_LINK(is_tcp=1) + enter_ready_tcp
- etcp_connect: TCP addrs -> etcp_tcp_link_start_connect
- Remove ctx->tcp_link/tcp_ready
- test_stcp_traffic: find stcp_link via links->is_tcp instead of transport_link
- 66/68 tests pass; 2 STCP tests expected to fail (integration not complete)

tools/chatgui/zxing-cpp/core/src/BitArray.cpp

@@ -1,38 +0,0 @@
-/*
-* Copyright 2016 Nu-book Inc.
-* Copyright 2016 ZXing authors
-*/
-// SPDX-License-Identifier: Apache-2.0
-
-#include "BitArray.h"
-
-#include "ByteArray.h"
-
-#include <cstddef>
-#include <stdexcept>
-
-namespace ZXing {
-
-void
-BitArray::bitwiseXOR(const BitArray& other)
-{
-	if (size() != other.size()) {
-		throw std::invalid_argument("BitArray::xor(): Sizes don't match");
-	}
-	for (size_t i = 0; i < _bits.size(); i++) {
-		// The last int could be incomplete (i.e. not have 32 bits in
-		// it) but there is no problem since 0 XOR 0 == 0.
-		_bits[i] ^= other._bits[i];
-	}
-}
-
-ByteArray BitArray::toBytes(int bitOffset, int numBytes) const
-{
-	ByteArray res(numBytes == -1 ? (size() - bitOffset + 7) / 8 : numBytes);
-	for (int i = 0; i < Size(res); i++)
-		for (int j = 0; j < 8; j++)
-			AppendBit(res[i], (numBytes != -1 || bitOffset < size()) ? get(bitOffset++) : false);
-	return res;
-}
-
-} // ZXing