Implemented by subclasses to scroll the receiver one line down in its scroll view, without changing the selection.
Original signature is '- (void)scrollLineDown:(id)sender'
Available in Mac OS X v10.0 and later.


- sender (Id)
- Typically the object that invoked this method.

- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)