Changes:

• Renamed UIEvent2D to UIToggle2
• Renamed UIEvent2DEditor to UIToggle2Editor
• Removed Clamping option from UIToggle2 class
• Added uniform and non uniform scaling to UIToggle2 class
• Added enum for UIEventType
• Added UIEventArgs class for UIEventArgument data
• Added UIEvent delegate
• Added Double_Click event to UIToggle2