Fix loading of selection masks

1) The active field should be saved correctly
2) The outline cache should be invalidated when loading

Fixes T568

krita/ui/kra/kis_kra_load_visitor.cpp

@@ -460,7 +460,7 @@ bool KisKraLoadVisitor::loadSelection(const QString& location, KisSelectionSP ds
         if (!result) {
             m_errorMessages << i18n("Could not load raster selection %1.", location);
         }
-
+        pixelSelection->invalidateOutlineCache();
     }
 
     // Shape selection
@@ -476,7 +476,6 @@ bool KisKraLoadVisitor::loadSelection(const QString& location, KisSelectionSP ds
         if (!result) {
             m_errorMessages << i18n("Could not load vector selection %1.", location);
         }
-
     }
     return result;
 }

krita/ui/kra/kis_kra_savexml_visitor.cpp

@@ -361,7 +361,7 @@ void KisSaveXmlVisitor::saveMask(QDomElement & el, const QString & maskType, con
     el.setAttribute(UUID, mask->uuid().toString());
 
     if (maskType == SELECTION_MASK) {
-        el.setAttribute(ACTIVE, mask->nodeProperties().boolProperty("visible"));
+        el.setAttribute(ACTIVE, mask->nodeProperties().boolProperty("active"));
     }
 
     m_nodeFileNames[mask] = MASK + QString::number(m_count);