provide autoscale option for Qt plotting (bug #44307) * Canvas.h, Canvas.cc (Canvas::autoAxes): New pure virtual function. (Canvas::canvasAutoAxes): New function. (autoscale_axes): New static function. (Canvas::canvasMouseDoubleClickEvent, Canvas::canvasMousePressEvent): Use it. * Figure.h, Figure.cc (Figure::createFigureToolBarAndMenuBar): Add autoscale button to window. (Figure::autoAxes): New function. * GLCanvas.h, GLCanvas.cc (GLCanvas::autoAxes): New function.

--- a/libgui/graphics/GLCanvas.cc	Thu Feb 26 18:57:58 2015 -0600
+++ b/libgui/graphics/GLCanvas.cc	Fri Feb 27 11:24:12 2015 -0500
@@ -70,6 +70,11 @@
   canvasToggleGrid (gh);
 }
 
+void GLCanvas::autoAxes (const graphics_handle& gh)
+{
+  canvasAutoAxes (gh);
+}
+
 graphics_object GLCanvas::selectFromAxes (const graphics_object& ax,
                                           const QPoint& pt)
 {