Added resumable loading, along with signal handling.

This version can store state after receiving SIGINT.
This is achieved by polling FIFO read state;

Controller.cpp

@@ -0,0 +1,48 @@
+#include "Controller.hpp"
+#include "u2f.hpp"
+#include <iostream>
+#include "IO.hpp"
+
+using namespace std;
+
+Controller::Controller(const uint32_t startChannel)
+	: channels{}, currChannel{ startChannel }
+{}
+
+void Controller::handleTransaction()
+{
+	auto msg = U2FMessage::readNonBlock();
+
+	if (!msg)
+		return;
+
+	auto opChannel = msg->cid;
+
+	clog << "Got msg with cmd of: " << static_cast<uint16_t>(msg->cmd) << endl;
+
+	if (msg->cmd == U2FHID_INIT)
+	{
+		opChannel = nextChannel();
+		auto channel = Channel{ opChannel };
+
+		try
+		{
+			channels.emplace(opChannel, channel); //In case of wrap-around replace existing one
+		}
+		catch (...)
+		{
+			channels.insert(make_pair(opChannel, channel));
+		}
+	}
+
+	channels.at(opChannel).handle(msg);
+}
+
+const uint32_t Controller::nextChannel()
+{
+	do
+		currChannel++;
+	while (currChannel == 0xFFFFFFFF || currChannel == 0);
+
+	return currChannel;
+}