Adjustments to theme.textColor changes

The larger headings are a bit softened, to make their stick out less,
the font is meant to take care of this. Result: visually more consistent
colouring, strangely. Human eyes are beautifully complex things.

src/declarativeimports/plasmaextracomponents/qml/Heading.qml

@@ -57,6 +57,7 @@ Label {
 
     font.pointSize: headerPointSize(level)
     wrapMode: Text.WordWrap
+    opacity: 0.8
 
     function headerPointSize(l) {
         var n = theme.defaultFont.pointSize;

src/declarativeimports/plasmaextracomponents/qml/Title.qml

@@ -42,6 +42,7 @@ import org.kde.plasma.components 2.0
  */
 Label {
     id: root
+    opacity: 0.8
 
     font.pointSize: theme.defaultFont.pointSize*2
 }