Qt: Add option to hide the system tray icon

My changes leave all tray icon and menu creation/initialization logic
untouched. It only shows or hides the icon according to the setting.

A new checkbox was added to the OptionsDialog under the Window tab. A
bool option named "hideTrayIcon" was added to OptionsModel. This
checkbox was mapped like other all options to the OptionsModel.

A signal was added to the OptionsModel for broadcasting changes the the
hideTrayIcon option. This signal was connected to a new slot added to
BitcoinGUI named setTrayIconVisible(bool). The slot simply hides or
shows the trayIcon in BitcoinGUI according to the parameter recieved.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/qt/optionsdialog.h b/src/qt/optionsdialog.h
index e944fb9ee9..41b56d1386 100644
--- a/src/qt/optionsdialog.h
+++ b/src/qt/optionsdialog.h
@@ -49,6 +49,8 @@ private Q_SLOTS:
     void on_resetButton_clicked();
     void on_okButton_clicked();
     void on_cancelButton_clicked();
+    
+    void on_hideTrayIcon_stateChanged(int fState);
 
     void showRestartWarning(bool fPersistent = false);
     void clearStatusLabel();