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/doc/man/man3/QwtCompassMagnetNeedle.3

@@ -0,0 +1,99 @@
+.TH "QwtCompassMagnetNeedle" 3 "Mon Jun 1 2020" "Version 6.1.5" "Qwt User's Guide" \" -*- nroff -*-
+.ad l
+.nh
+.SH NAME
+QwtCompassMagnetNeedle \- A magnet needle for compass widgets\&.  
+
+.SH SYNOPSIS
+.br
+.PP
+.PP
+\fC#include <qwt_dial_needle\&.h>\fP
+.PP
+Inherits \fBQwtDialNeedle\fP\&.
+.SS "Public Types"
+
+.in +1c
+.ti -1c
+.RI "enum \fBStyle\fP { \fBTriangleStyle\fP, \fBThinStyle\fP }"
+.br
+.RI "Style of the needle\&. "
+.in -1c
+.SS "Public Member Functions"
+
+.in +1c
+.ti -1c
+.RI "\fBQwtCompassMagnetNeedle\fP (\fBStyle\fP=\fBTriangleStyle\fP, const QColor &light=Qt::white, const QColor &dark=Qt::red)"
+.br
+.RI "Constructor\&. "
+.in -1c
+.SS "Protected Member Functions"
+
+.in +1c
+.ti -1c
+.RI "virtual void \fBdrawNeedle\fP (QPainter *, double length, QPalette::ColorGroup) const"
+.br
+.in -1c
+.SH "Detailed Description"
+.PP 
+A magnet needle for compass widgets\&. 
+
+A magnet needle points to two opposite directions indicating north and south\&.
+.PP
+The following colors are used:
+.IP "\(bu" 2
+QPalette::Light
+.br
+ Used for pointing south
+.IP "\(bu" 2
+QPalette::Dark
+.br
+ Used for pointing north
+.IP "\(bu" 2
+QPalette::Base
+.br
+ Knob (ThinStyle only)
+.PP
+.PP
+\fBSee also\fP
+.RS 4
+\fBQwtDial\fP, \fBQwtCompass\fP 
+.RE
+.PP
+
+.SH "Member Enumeration Documentation"
+.PP 
+.SS "enum \fBQwtCompassMagnetNeedle::Style\fP"
+
+.PP
+Style of the needle\&. 
+.PP
+\fBEnumerator\fP
+.in +1c
+.TP
+\fB\fITriangleStyle \fP\fP
+A needle with a triangular shape\&. 
+.TP
+\fB\fIThinStyle \fP\fP
+A thin needle\&. 
+.SH "Member Function Documentation"
+.PP 
+.SS "void QwtCompassMagnetNeedle::drawNeedle (QPainter * painter, double length, QPalette::ColorGroup colorGroup) const\fC [protected]\fP, \fC [virtual]\fP"
+Draw the needle
+.PP
+\fBParameters\fP
+.RS 4
+\fIpainter\fP Painter 
+.br
+\fIlength\fP Length of the needle 
+.br
+\fIcolorGroup\fP Color group, used for painting 
+.RE
+.PP
+
+.PP
+Implements \fBQwtDialNeedle\fP\&.
+
+.SH "Author"
+.PP 
+Generated automatically by Doxygen for Qwt User's Guide from the source code\&.