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_zoneitem.h

@@ -0,0 +1,65 @@
+/* -*- 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_ZONE_ITEM_H
+#define QWT_PLOT_ZONE_ITEM_H
+
+#include "qwt_global.h"
+#include "qwt_plot_item.h"
+#include "qwt_interval.h"
+
+class QPen;
+class QBrush;
+
+/*!
+  \brief A plot item, which displays a zone
+
+  A horizontal zone highlights an interval of the y axis - a vertical
+  zone an interval of the x axis - and is unbounded in the opposite direction.
+  It is filled with a brush and its border lines are optionally displayed with a pen.
+
+  \note For displaying an area that is bounded for x and y coordinates
+        use QwtPlotShapeItem
+*/
+
+class QWT_EXPORT QwtPlotZoneItem:
+    public QwtPlotItem
+{
+public:
+    explicit QwtPlotZoneItem();
+    virtual ~QwtPlotZoneItem();
+
+    virtual int rtti() const;
+
+    void setOrientation( Qt::Orientation );
+    Qt::Orientation orientation();
+
+    void setInterval( double min, double max );
+    void setInterval( const QwtInterval & );
+    QwtInterval interval() const;
+
+    void setPen( const QColor &, qreal width = 0.0, Qt::PenStyle = Qt::SolidLine );
+    void setPen( const QPen & );
+    const QPen &pen() const;
+
+    void setBrush( const QBrush & );
+    const QBrush &brush() const;
+
+    virtual void draw( QPainter *,
+        const QwtScaleMap &, const QwtScaleMap &,
+        const QRectF &) const;
+
+    virtual QRectF boundingRect() const;
+
+private:
+    class PrivateData;
+    PrivateData *d_data;
+};
+
+#endif