Fix minor EBN issues

kexthighscore_gui.h

@@ -56,7 +56,7 @@ class ScoresList : public QTreeWidget
 {
  Q_OBJECT
  public:
-    ScoresList(QWidget *parent);
+    explicit ScoresList(QWidget *parent);
 
     void addHeader(const ItemArray &);
 

kexthighscore_internal.h

@@ -180,7 +180,7 @@ class ScoreInfos : public ItemArray
 class ConfigGroup : public KConfigGroup
 {
  public:
-    ConfigGroup(const QString &group = QLatin1String( "" ))
+    explicit ConfigGroup(const QString &group = QLatin1String( "" ))
         : KConfigGroup(KSharedConfig::openConfig(), group) {}
 };
 

kexthighscore_item.cpp

@@ -173,7 +173,7 @@ bool Score::isTheWorst() const
     return score()==s.score();
 }
 
-bool Score::operator <(const Score &score)
+bool Score::operator <(const Score &score) const
 {
     return internal->manager.isStrictlyLess(*this, score);
 }

kexthighscore_item.h

@@ -178,7 +178,7 @@ class Score;
 class  Score
 {
  public:
-    Score(ScoreType type = Won);
+    explicit Score(ScoreType type = Won);
 
     ~Score();
 
@@ -229,7 +229,7 @@ class  Score
      *
      * @see Manager::isStrictlyLess
      */
-    bool operator <(const Score &score);
+    bool operator <(const Score &score) const;
 
  private:
     ScoreType  _type;

kexthighscore_tab.h

@@ -35,7 +35,7 @@ class PlayersCombo : public QComboBox
 {
  Q_OBJECT
  public:
-    PlayersCombo(QWidget *parent = nullptr);
+    explicit PlayersCombo(QWidget *parent = nullptr);
 
     void load();
 
@@ -53,7 +53,7 @@ class AdditionalTab : public QWidget
 {
  Q_OBJECT
  public:
-    AdditionalTab(QWidget *parent);
+    explicit AdditionalTab(QWidget *parent);
 
     virtual void load();
 
@@ -100,7 +100,7 @@ class HistogramTab : public AdditionalTab
 {
  Q_OBJECT
  public:
-    HistogramTab(QWidget *parent);
+    explicit HistogramTab(QWidget *parent);
 
     void load() override;