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_grid.h

@@ -0,0 +1,87 @@
+/* -*- 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_GRID_H
+#define QWT_PLOT_GRID_H
+
+#include "qwt_global.h"
+#include "qwt_plot_item.h"
+#include "qwt_scale_div.h"
+
+class QPainter;
+class QPen;
+class QwtScaleMap;
+class QwtScaleDiv;
+
+/*!
+  \brief A class which draws a coordinate grid
+
+  The QwtPlotGrid class can be used to draw a coordinate grid.
+  A coordinate grid consists of major and minor vertical
+  and horizontal grid lines. The locations of the grid lines
+  are determined by the X and Y scale divisions which can
+  be assigned with setXDiv() and setYDiv().
+  The draw() member draws the grid within a bounding
+  rectangle.
+*/
+
+class QWT_EXPORT QwtPlotGrid: public QwtPlotItem
+{
+public:
+    explicit QwtPlotGrid();
+    virtual ~QwtPlotGrid();
+
+    virtual int rtti() const;
+
+    void enableX( bool );
+    bool xEnabled() const;
+
+    void enableY( bool );
+    bool yEnabled() const;
+
+    void enableXMin( bool );
+    bool xMinEnabled() const;
+
+    void enableYMin( bool );
+    bool yMinEnabled() const;
+
+    void setXDiv( const QwtScaleDiv & );
+    const QwtScaleDiv &xScaleDiv() const;
+
+    void setYDiv( const QwtScaleDiv & );
+    const QwtScaleDiv &yScaleDiv() const;
+
+    void setPen( const QColor &, qreal width = 0.0, Qt::PenStyle = Qt::SolidLine );
+    void setPen( const QPen & );
+
+    void setMajorPen( const QColor &, qreal width = 0.0, Qt::PenStyle = Qt::SolidLine );
+    void setMajorPen( const QPen & );
+    const QPen& majorPen() const;
+
+    void setMinorPen( const QColor &, qreal width = 0.0, Qt::PenStyle = Qt::SolidLine );
+    void setMinorPen( const QPen & );
+    const QPen& minorPen() const;
+
+    virtual void draw( QPainter *,
+        const QwtScaleMap &xMap, const QwtScaleMap &yMap,
+        const QRectF &canvasRect ) const;
+
+    virtual void updateScaleDiv(
+        const QwtScaleDiv &xScaleDiv, const QwtScaleDiv &yScaleDiv );
+
+private:
+    void drawLines( QPainter *, const QRectF &,
+        Qt::Orientation, const QwtScaleMap &,
+        const QList<double> & ) const;
+
+    class PrivateData;
+    PrivateData *d_data;
+};
+
+#endif