Qt5 built in qwt (#570)

- qt4->qt5
- in built qt5 6.1.5 because rhel7 is not upto date with qt5, removed findqwt.cmake
- made a fix in qwt lib (qwt_plot_layout.h) to work with 5.15 and lower versions for qrect constr.
- qt5 forms fixed, qt4 many hard coding forms switched to forms including qtabwidget, scrolls etc, fonts moved to forms
 - docking option enabled by default, removed option to disable docking feature from "Mode"
- added qVersionResolve utility functions to handle compatibility before and after qt5.12
- qtplots (ian's code) takes in gain mode enable to set some settings within the class, with proper gain plot ticks
- ensure gain plots have no zooming of z axis in 2d and y axis in 1d
- removed placeholder text in qpalette in main window form as its not supportd until 5.12 (so using qt5.9 designer insted of qt5.15 to cope)
- tab order
Servers:
- fixed some error messages that were empty for fail in funcs (mostly minor as if this error, major issues)

libs/qwt-6.1.5/include/qwt_plot_panner.h

@@ -0,0 +1,60 @@
+/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
+ * Qwt Widget Library
+ * Copyright (C) 1997   Josef Wilgen
+ * Copyright (C) 2002   Uwe Rathmann
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the Qwt License, Version 1.0
+ *****************************************************************************/
+
+#ifndef QWT_PLOT_PANNER_H
+#define QWT_PLOT_PANNER_H 1
+
+#include "qwt_global.h"
+#include "qwt_panner.h"
+
+class QwtPlot;
+
+/*!
+  \brief QwtPlotPanner provides panning of a plot canvas
+
+  QwtPlotPanner is a panner for a plot canvas, that
+  adjusts the scales of the axes after dropping
+  the canvas on its new position.
+
+  Together with QwtPlotZoomer and QwtPlotMagnifier powerful ways
+  of navigating on a QwtPlot widget can be implemented easily.
+
+  \note The axes are not updated, while dragging the canvas
+  \sa QwtPlotZoomer, QwtPlotMagnifier
+*/
+class QWT_EXPORT QwtPlotPanner: public QwtPanner
+{
+    Q_OBJECT
+
+public:
+    explicit QwtPlotPanner( QWidget * );
+    virtual ~QwtPlotPanner();
+
+    QWidget *canvas();
+    const QWidget *canvas() const;
+
+    QwtPlot *plot();
+    const QwtPlot *plot() const;
+
+    void setAxisEnabled( int axis, bool on );
+    bool isAxisEnabled( int axis ) const;
+
+protected Q_SLOTS:
+    virtual void moveCanvas( int dx, int dy );
+
+protected:
+    virtual QBitmap contentsMask() const;
+    virtual QPixmap grab() const;
+
+private:
+    class PrivateData;
+    PrivateData *d_data;
+};
+
+#endif