Use PascalCase for Qt client filenames

Split FileTree.{h,cc} and FilterBar.{h,cc} files so that each class
is in its own file.

This breaks translations (some classes got renamed => context changed),
to be fixed by next commit (along with Tx sync).

qt/RpcClient.h

@@ -0,0 +1,77 @@
+/*
+ * This file Copyright (C) 2014-2015 Mnemosyne LLC
+ *
+ * It may be used under the GNU GPL versions 2 or 3
+ * or any future license endorsed by Mnemosyne LLC.
+ *
+ * $Id$
+ */
+
+#ifndef QTR_RPC_CLIENT_H
+#define QTR_RPC_CLIENT_H
+
+#include <QNetworkReply>
+#include <QObject>
+#include <QString>
+#include <QUrl>
+
+#include <libtransmission/transmission.h>
+#include <libtransmission/quark.h>
+
+class QByteArray;
+class QNetworkAccessManager;
+
+extern "C"
+{
+  struct evbuffer;
+  struct tr_session;
+  struct tr_variant;
+}
+
+class RpcClient: public QObject
+{
+    Q_OBJECT
+
+  public:
+    RpcClient (QObject * parent = nullptr);
+    virtual ~RpcClient () {}
+
+    void stop ();
+    void start (tr_session * session);
+    void start (const QUrl& url);
+
+    bool isLocal () const;
+    const QUrl& url () const;
+
+    void exec (tr_quark method, tr_variant * args, int64_t tag = -1);
+    void exec (const char* method, tr_variant * args, int64_t tag = -1);
+
+  signals:
+    void httpAuthenticationRequired ();
+    void dataReadProgress ();
+    void dataSendProgress ();
+    void error (QNetworkReply::NetworkError code);
+    void errorMessage (const QString& message);
+    void executed (int64_t tag, const QString& result, tr_variant * args);
+
+    // private
+    void responseReceived (const QByteArray& json);
+
+  private:
+    void sendRequest (const QByteArray& json);
+    QNetworkAccessManager * networkAccessManager ();
+
+    static void localSessionCallback (tr_session * s, evbuffer * json, void * vself);
+
+  private slots:
+    void onFinished (QNetworkReply * reply);
+    void parseResponse (const QByteArray& json);
+
+  private:
+    tr_session * mySession;
+    QString mySessionId;
+    QUrl myUrl;
+    QNetworkAccessManager * myNAM;
+};
+
+#endif // QTR_RPC_CLIENT_H