NOISSUE refactor *Download into more, smaller pieces

* Download is now Download.
* Download uses Sink subclasses to process various events.
* Validators can be used to further customize the Sink behaviour.

api/logic/net/Validator.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "net/NetAction.h"
+
+#include "multimc_logic_export.h"
+
+namespace Net {
+class MULTIMC_LOGIC_EXPORT Validator
+{
+public: /* con/des */
+	Validator() {};
+	virtual ~Validator() {};
+
+public: /* methods */
+	virtual bool init(QNetworkRequest & request) = 0;
+	virtual bool write(QByteArray & data) = 0;
+	virtual bool abort() = 0;
+	virtual bool validate(QNetworkReply & reply) = 0;
+};
+}