Embedded R Tweaks

.. Hi-dpi support fixes use of OpenGL acceleration
.. Added a bit of debug on startup (when GC_WANT_ALLDEBUG is set)

src/Charts/RCanvas.cpp

@@ -52,8 +52,8 @@ RCanvas::RCanvas(Context *context, QWidget *parent) : QGraphicsView(parent), con
 
 #ifdef Q_OS_LINUX // mac and windows both have issues. sigh.
     //disabled for now as Linux also has issues on High DPI screen
-    //setViewport(new QGLWidget( QGLFormat(QGL::SampleBuffers)));
-    //setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
+    setViewport(new QGLWidget( QGLFormat(QGL::SampleBuffers)));
+    setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
 #endif
 
     // allow to click and drag

src/R/RLibrary.cpp

@@ -456,5 +456,6 @@ RLibrary::load()
         // sadly, there is no standard place on windows
         setenv("R_HOME", home.toLatin1().constData(), true);
     }
+
     return loaded;
 }

src/R/RTool.cpp

@@ -154,6 +154,11 @@ RTool::RTool()
             if (exp.exactMatch(strings[1])) version = exp.cap(1);
             else version = strings[1];
         }
+
+        // what version are we running?
+        #ifdef GC_WANT_ALLDEBUG
+        fprintf(stderr,"R loaded. [Compiled=%s.%s, Loaded=%s, Loaded DeviceEngine=%d]\n", R_MAJOR, R_MINOR, version.toStdString().c_str(), GC_R_GE_getVersion());
+        #endif
         rtool->messages.clear();
 
         // load the dynamix library and create function wrapper