fix compilation with gcc in paranoic mode

deckview.cpp:244:6: warning: no previous declaration for 'bool
sortCardsByName(DeckViewCard*, DeckViewCard*)' [-Wmissing-declarations]

cockatrice/src/deckview.cpp

@@ -241,7 +241,7 @@ QSizeF DeckViewCardContainer::calculateBoundingRect(const QList<QPair<int, int>
     return QSizeF(getCardTypeTextWidth() + totalWidth, totalHeight + separatorY + paddingY);
 }
 
-bool sortCardsByName(DeckViewCard * c1, DeckViewCard * c2)
+bool DeckViewCardContainer::sortCardsByName(DeckViewCard * c1, DeckViewCard * c2)
 {
     if (c1 && c2)
        return c1->getName() < c2->getName();
@@ -264,7 +264,7 @@ void DeckViewCardContainer::rearrangeItems(const QList<QPair<int, int> > &rowsAn
         
         QList<QString> cardTypeList = cardsByType.uniqueKeys();
         QList<DeckViewCard *> row = cardsByType.values(cardTypeList[i]);
-        qSort( row.begin(), row.end(), sortCardsByName);
+        qSort( row.begin(), row.end(), DeckViewCardContainer::sortCardsByName);
         for (int j = 0; j < row.size(); ++j) {
             DeckViewCard *card = row[j];
             card->setPos(x + (j % tempCols) * CARD_WIDTH, yUntilNow + (j / tempCols) * CARD_HEIGHT);

cockatrice/src/deckview.h

@@ -46,6 +46,7 @@ class DeckViewCardContainer : public QGraphicsItem {
 private:
     static const int separatorY = 20;
     static const int paddingY = 10;
+    static bool sortCardsByName(DeckViewCard * c1, DeckViewCard * c2);
     
     QString name;
     QList<DeckViewCard *> cards;