ProjectExplorer: Add settings icon to app and compile output panes

This provides a natural shortcut to the respective options page.

Change-Id: I1e57c64d1541540cb1c0c44c6fb8eaad69fc2e32
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/projectexplorer/compileoutputwindow.h

@@ -99,6 +99,7 @@ private:
     QToolButton *m_cancelBuildButton;
     QToolButton *m_zoomInButton;
     QToolButton *m_zoomOutButton;
+    QToolButton * const m_settingsButton;
     Utils::OutputFormatter *m_formatter;
     CompileOutputSettings m_settings;
 };