Message: Create a type system so non-frame data can be represented

This change breaks existing code, hence the version bump, but it's
going to be much less error prone going forward.

include/icsneo/communication/message/ethernetmessage.h

@@ -31,7 +31,7 @@ struct MACAddress {
 	}
 };
 
-class EthernetMessage : public Message {
+class EthernetMessage : public Frame {
 public:
 	bool preemptionEnabled = false;
 	uint8_t preemptionFlags = 0;