Fix a couple of clang compiler warnings:

-Wunused-variable
-Winconsistent-missing-override
-Wdelete-non-virtual-dtor
-Wunused-private-field
-Wformat

src/Mod/TechDraw/App/DrawViewPart.cpp

@@ -118,8 +118,7 @@ using namespace std;
 PROPERTY_SOURCE(TechDraw::DrawViewPart, TechDraw::DrawView)
 
 DrawViewPart::DrawViewPart(void) : 
-    geometryObject(0),
-    on1(true)
+    geometryObject(0)
 {
     static const char *group = "Projection";
     static const char *sgroup = "HLR Parameters";

src/Mod/TechDraw/App/DrawViewPart.h

@@ -218,7 +218,6 @@ protected:
 
 private:
     bool nowUnsetting;
-    bool on1;
 /*    bool m_restoreComplete;*/
 
 };

src/Mod/TechDraw/Gui/QGMText.cpp

@@ -49,7 +49,7 @@ QGMText::QGMText() :
 
 QVariant QGMText::itemChange(GraphicsItemChange change, const QVariant &value)
 {
-    QPointF newPos(0.0,0.0);
+    //QPointF newPos(0.0,0.0);
     if(change == ItemPositionHasChanged && scene()) {
         Q_EMIT dragging();
     }

src/Mod/TechDraw/Gui/QGTracker.cpp

@@ -52,11 +52,9 @@
 using namespace TechDrawGui;
 
 QGTracker::QGTracker(QGraphicsScene* inScene, TrackerMode m):
-    m_width(0),
     m_sleep(false),
     m_qgParent(nullptr),
-    m_lastClick(QPointF(FLT_MAX,FLT_MAX)),
-    m_2clickPending(false)
+    m_lastClick(QPointF(FLT_MAX,FLT_MAX))
 {
     setTrackerMode(m);
     if (inScene != nullptr) {

src/Mod/TechDraw/Gui/QGTracker.h

@@ -92,7 +92,6 @@ protected:
     double getTrackerWeight();
 
 private:
-    double m_width;
     QGraphicsPathItem* m_track;
     QPointF m_segBegin;
     QPointF m_segEnd;
@@ -103,7 +102,6 @@ private:
     QPen m_trackPen;
     QPen m_tailPen;
     QPointF m_lastClick;
-    bool m_2clickPending;
 };
 
 } // namespace

src/Mod/TechDraw/Gui/ViewProviderPage.h

@@ -98,7 +98,6 @@ private:
     QPointer<MDIViewPage> m_mdiView;
     bool m_docReady;
     std::string m_pageName;
-    bool m_frameState;
     QGVPage* m_graphicsView;
 };