[ESS] fix current line while scrolling

[Stephen Eglen]

> 
> does anyone of you know how to switch off the automatic movement of
> the "current line" when scrolling through an emacs buffer ? 
> 
> Currently whenever I scroll through some R script, the current line is
> also "scrolled" whenever it would be outside the visible region.


> This is very annoying whenever I try to find matching parentheses and
> the block of code is larger than the buffer as the parentheses. In
> such a case the highlighting of the matching parenthesis always
> disappears as soon as I scroll too far.
Dear Jannis,

I don't quite follow what you mean in the first two paragraphs.
However, you might like to see the advice on this code -- it helps you
jump between matching parens, rather than just highlighting which one
matches.
  http://www.emacswiki.org/emacs/ParenthesisMatching

Stephen