Use the forge mirrors for downloading forge libraries

Let's hope we never, ever see a forge download error again.

logic/net/ForgeMirrors.h

@@ -0,0 +1,58 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "NetAction.h"
+#include "HttpMetaCache.h"
+#include "ForgeXzDownload.h"
+#include "NetJob.h"
+#include <QFile>
+#include <QTemporaryFile>
+typedef std::shared_ptr<class ForgeMirrors> ForgeMirrorsPtr;
+
+class ForgeMirrors : public NetAction
+{
+	Q_OBJECT
+public:
+	QList<ForgeXzDownloadPtr> m_libs;
+	NetJobPtr m_parent_job;
+	QList<ForgeMirror> m_mirrors;
+
+public:
+	explicit ForgeMirrors(QList<ForgeXzDownloadPtr> &libs, NetJobPtr parent_job,
+						  QString mirrorlist);
+	static ForgeMirrorsPtr make(QList<ForgeXzDownloadPtr> &libs, NetJobPtr parent_job,
+								QString mirrorlist)
+	{
+		return ForgeMirrorsPtr(new ForgeMirrors(libs, parent_job, mirrorlist));
+	}
+
+protected
+slots:
+	virtual void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
+	virtual void downloadError(QNetworkReply::NetworkError error);
+	virtual void downloadFinished();
+	virtual void downloadReadyRead();
+
+private:
+	void parseMirrorList();
+	void deferToFixedList();
+	void injectDownloads();
+
+public
+slots:
+	virtual void start();
+};