GUI: serialization refactoring part 7

The the rest of classes have got readFrom and writeTo methods.

Serialization of instruments is done.

The rest of work is to remove all usages and mentions of serialization.

GUI/Model/Device/MaskItems.cpp

@@ -916,19 +916,14 @@ std::unique_ptr<IShape2D> MaskAllItem::createShape(double) const
 
 void MaskAllItem::serialize(Streamer& s)
 {
-    s.assertVersion(0);
-    Serialize::rwSessionItem<bool>(s, "maskValue", getItem(P_MASK_VALUE));
-    Serialize::rwSessionItem<bool>(s, "visible", getItem(P_IS_VISIBLE));
-}
-
-void MaskAllItem::writeTo(QXmlStreamWriter *w) const
-{
-
-}
-
-void MaskAllItem::readFrom(QXmlStreamReader *r)
-{
+//    s.assertVersion(0);
+//    Serialize::rwSessionItem<bool>(s, "maskValue", getItem(P_MASK_VALUE));
+//    Serialize::rwSessionItem<bool>(s, "visible", getItem(P_IS_VISIBLE));
 
+    if (s.xmlReader())
+        readFrom(s.xmlReader());
+    else if (s.xmlWriter())
+        writeTo(s.xmlWriter());
 }
 
 /* ------------------------------------------------------------------------- */