fix windows build and some deprecation warnings

Author: jef-n

src/core/raster/qgsrasterlayer.cpp

@@ -1076,7 +1076,7 @@ QList< QPair< QString, QColor > > QgsRasterLayer::legendSymbologyItems() const
  */
 QPixmap QgsRasterLayer::legendAsPixmap()
 {
-  return legendAsPixmap( false );
+  return QPixmap();
 }
 
 /**
@@ -1740,14 +1740,6 @@ void QgsRasterLayer::setDataProvider( QString const & provider )
     mRasterType = GrayOrUndefined;
   }
 
-  // Set min/max values for single band if we have them ready (no need to calculate which is slow)
-  // don't set min/max on multiband even if available because it would cause stretch of bands and thus colors distortion
-  if ( mDataProvider->bandCount() == 1 && ( mDataProvider->capabilities() & QgsRasterDataProvider::ExactMinimumMaximum ) )
-  {
-    setMinimumValue( 1, mDataProvider->minimumValue( 1 ) );
-    setMaximumValue( 1, mDataProvider->maximumValue( 1 ) );
-  }
-
   QgsDebugMsg( "mRasterType = " + QString::number( mRasterType ) );
   if ( mRasterType == ColorLayer )
   {

src/gui/raster/qgsrasterhistogramwidget.h

@@ -34,7 +34,7 @@ typedef QPointF QwtDoublePoint;
   *@author Etienne Tourigny
   */
 
-class QgsRasterHistogramWidget : public QWidget, private Ui::QgsRasterHistogramWidgetBase
+class GUI_EXPORT QgsRasterHistogramWidget : public QWidget, private Ui::QgsRasterHistogramWidgetBase
 {
     Q_OBJECT