Remove redundant suffix from TorrentHandle class

Originally, it was just a wrapper for libtorrent::torrent_handle class, so it mimicked its name.
It was then transformed into a more complex aggregate, but the name was retained (just by inertia).
Unlike libtorrent::torrent_handle class in whose name "handle" means the pattern used,
it does not matter for qBittorrent classes and just eats up space in the source code.

src/base/bittorrent/torrent.cpp

@@ -0,0 +1,73 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2015  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2006  Christophe Dumez <chris@qbittorrent.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#include "torrent.h"
+
+#include <type_traits>
+
+#include <QHash>
+
+namespace BitTorrent
+{
+    uint qHash(const TorrentState key, const uint seed)
+    {
+        return ::qHash(static_cast<std::underlying_type_t<TorrentState>>(key), seed);
+    }
+
+    // Torrent
+
+    const qreal Torrent::USE_GLOBAL_RATIO = -2.;
+    const qreal Torrent::NO_RATIO_LIMIT = -1.;
+
+    const int Torrent::USE_GLOBAL_SEEDING_TIME = -2;
+    const int Torrent::NO_SEEDING_TIME_LIMIT = -1;
+
+    const qreal Torrent::MAX_RATIO = 9999.;
+    const int Torrent::MAX_SEEDING_TIME = 525600;
+
+    bool Torrent::isResumed() const
+    {
+        return !isPaused();
+    }
+
+    qlonglong Torrent::remainingSize() const
+    {
+        return wantedSize() - completedSize();
+    }
+
+    void Torrent::toggleSequentialDownload()
+    {
+        setSequentialDownload(!isSequentialDownload());
+    }
+
+    void Torrent::toggleFirstLastPiecePriority()
+    {
+        setFirstLastPiecePriority(!hasFirstLastPiecePriority());
+    }
+}