BT composite that executes tasks in turn until first [code]SUCCESS[/code]. BT composite that executes child tasks from first to last until any child returns [code]SUCCESS[/code]. Returns [code]RUNNING[/code] if a task returns [code]RUNNING[/code], and remembers last [code]RUNNING[/code] child. BTSelector will continue where it left off on the next execution tick. Returns [code]FAILURE[/code] if all tasks return [code]FAILURE[/code]. Returns [code]SUCCESS[/code] if any task returns [code]SUCCESS[/code].