Make List of Clients in ClientGroup accessable in scripts

For that ClientList is exported as a sequence meta type and
property is added to ClientGroup.

client.h

@@ -1178,5 +1178,6 @@ KWIN_COMPARE_PREDICATE(InputIdMatchPredicate, Client, Window, cl->inputId() == v
 
 } // namespace
 Q_DECLARE_METATYPE(KWin::Client*)
+Q_DECLARE_METATYPE(QList<KWin::Client*>)
 
 #endif

clientgroup.h

@@ -69,6 +69,10 @@ class ClientGroup : public QObject
      * The index of the visible Client in this group.
      **/
     Q_PROPERTY(int visibleClientIndex READ indexOfVisibleClient NOTIFY visibleChanged)
+    /**
+     * The Clients in this group.
+     **/
+    Q_PROPERTY(QList<KWin::Client*> clients READ clients)
 public:
     /**
      * Creates a new group containing \p c.

scripting/meta.cpp

@@ -132,6 +132,7 @@ void KWin::MetaScripting::registration(QScriptEngine* eng)
 
     qScriptRegisterSequenceMetaType<QStringList>(eng);
     qScriptRegisterSequenceMetaType< QList<KWin::ClientGroup*> >(eng);
+    qScriptRegisterSequenceMetaType< QList<KWin::Client*> >(eng);
 }
 
 QScriptValue KWin::MetaScripting::configExists(QScriptContext* ctx, QScriptEngine* eng)