AutoTest: Provide setting to outvote automatically disabling parser

Test parser is normally disabled as long neither test tree nor results
pane is opened. The new setting allows the user to enable the parser
without the need to have one of these widgets opened.

Task-number: QTCREATORBUG-15669
Change-Id: I354e1a3cb91eeca2302f2344fd443c81c4b15406
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@theqtcompany.com>
Reviewed-by: Niels Weber <niels.weber@theqtcompany.com>

src/plugins/autotest/testtreemodel.h

@@ -54,7 +54,9 @@ public:
     static TestTreeModel* instance();
     ~TestTreeModel();
     void enableParsing();
+    void enableParsingFromSettings();
     void disableParsing();
+    void disableParsingFromSettings();
 
     bool setData(const QModelIndex &index, const QVariant &value, int role) override;
     Qt::ItemFlags flags(const QModelIndex &index) const override;
@@ -100,6 +102,7 @@ private:
     void modifyTestSubtree(QModelIndex &toBeModifiedIndex, const TestTreeItem *newItem);
     void processChildren(QModelIndex &parentIndex, const TestTreeItem *newItem,
                          const int upperBound, const QHash<QString, Qt::CheckState> &checkStates);
+    void setupParsingConnections();
 
     TestTreeItem *m_autoTestRootItem;
     TestTreeItem *m_quickTestRootItem;