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_date_scale_engine.h

@@ -0,0 +1,86 @@
+/* -*- 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_DATE_SCALE_ENGINE_H_
+#define _QWT_DATE_SCALE_ENGINE_H_ 1
+
+#include "qwt_date.h"
+#include "qwt_scale_engine.h"
+
+/*!
+  \brief A scale engine for date/time values
+
+  QwtDateScaleEngine builds scales from a time intervals.
+  Together with QwtDateScaleDraw it can be used for
+  axes according to date/time values.
+
+  Years, months, weeks, days, hours and minutes are organized
+  in steps with non constant intervals. QwtDateScaleEngine
+  classifies intervals and aligns the boundaries and tick positions
+  according to this classification.
+
+  QwtDateScaleEngine supports representations depending
+  on Qt::TimeSpec specifications. The valid range for scales
+  is limited by the range of QDateTime, that differs
+  between Qt4 and Qt5.
+
+  Datetime values are expected as the number of milliseconds since
+  1970-01-01T00:00:00 Universal Coordinated Time - also known
+  as "The Epoch", that can be converted to QDateTime using
+  QwtDate::toDateTime().
+
+  \sa QwtDate, QwtPlot::setAxisScaleEngine(),
+      QwtAbstractScale::setScaleEngine()
+*/
+class QWT_EXPORT QwtDateScaleEngine: public QwtLinearScaleEngine
+{
+public:
+    QwtDateScaleEngine( Qt::TimeSpec = Qt::LocalTime );
+    virtual ~QwtDateScaleEngine();
+
+    void setTimeSpec( Qt::TimeSpec );
+    Qt::TimeSpec timeSpec() const;
+
+    void setUtcOffset( int seconds );
+    int utcOffset() const;
+
+    void setWeek0Type( QwtDate::Week0Type );
+    QwtDate::Week0Type week0Type() const;
+
+    void setMaxWeeks( int );
+    int maxWeeks() const;
+
+    virtual void autoScale( int maxNumSteps,
+        double &x1, double &x2, double &stepSize ) const;
+
+    virtual QwtScaleDiv divideScale(
+        double x1, double x2,
+        int maxMajorSteps, int maxMinorSteps,
+        double stepSize = 0.0 ) const;
+
+    virtual QwtDate::IntervalType intervalType(
+        const QDateTime &, const QDateTime &, int maxSteps ) const;
+
+    QDateTime toDateTime( double ) const;
+
+protected:
+    virtual QDateTime alignDate( const QDateTime &, double stepSize,
+        QwtDate::IntervalType, bool up ) const;
+
+private:
+    QwtScaleDiv buildScaleDiv( const QDateTime &, const QDateTime &,
+        int maxMajorSteps, int maxMinorSteps,
+        QwtDate::IntervalType ) const;
+
+private:
+    class PrivateData;
+    PrivateData *d_data;
+};
+
+#endif