Added registration.

Currently doesn't return any valid result, hence host believes device
failed to register, however, insecure storage of keys does occur.

U2FMessage.hpp

@@ -0,0 +1,14 @@
+#pragma once
+#include <cstdint>
+#include <vector>
+
+struct U2FMessage
+{
+	uint32_t        cid;
+	uint8_t         cmd;
+	std::vector<uint8_t> data;
+
+	static U2FMessage read();
+	
+	void write();
+};