The current design for some reason no longer worked very often, and there would be many situations
where the scrolling to follow the text output would stop and could never be recovered. Therefore
this feature has been redesigned.
In the LogCtrl element of the relax controller, which displays the relax output messages, the at_end
class boolean variable has been introduced. It defaults to True. The following events will turn it
off: Arrow keys, Home key, End key, Ctrl-Home key, Mouse button clicks, Mouse wheel scrolling,
Window thumbtrack scrolling (the side scrollbar), finding text, the pop up menu 'Go to start',
and Select all (menu or Ctrl-A). It will only be turned on in two cases: The pop up menu 'Go to
end', and if the caret is on the final line (caused by Ctrl-End, Mouse wheel scrolling, Page Down,
Down arrow, Window thumbtrack scrolling, etc.).
Three new methods have been introduced to handle certain events: capture_mouse() for mouse button
clicks, capture_mouse_wheel() for mouse wheel scrolling, and capture_scroll for window thumbtrack
scrolling.
