QML project executable file to default to lowercase .qml file

Use a lowercase .qml file found in project tree if no current file is
selected. This way we don't have to disable run controls if there are
some files to execute.

Reviewed-by: kkoehne

src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.h

@@ -72,8 +72,11 @@ public:
 
     QVariantMap toMap() const;
 
-private slots:
+public slots:
     void changeCurrentFile(Core::IEditor*);
+
+private slots:
+
     QString mainScript() const;
     void setMainScript(const QString &scriptFile);
 
@@ -102,6 +105,8 @@ private:
     QString m_debugServerAddress;
     uint m_debugServerPort;
 
+    Internal::QmlProjectTarget *m_projectTarget;
+
     bool m_usingCurrentFile;
     bool m_isEnabled;