Add click actions on icon on system notifcation area

[mindstormer12]

When "Show in notification area" is enabled, the following options are available:

• single-click to toggle timer on/off
• double-click to toggle window popup/minimize
• triple-click to restart timer with the time previously specified in the window
• automatically minimize window back to tray after a time has been entered

[rtmvnv]

At least it would be nice to have an ability to minimize it to system tray.