[ESS] proposal re: underscore

[Stephen Eglen]

> Anything that encourages people to use <- for assignment instead of =
> is a good thing, because it makes for more readable code, and I have
> tools that require it, in particular for creating an emacs TAGS file.

Slightly off topic, but a nice way of making TAGS files is using 'R CMD
rtags', from Deepayan:
  http://developer.r-project.org/rtags.html

This recognises functions defined either with '<-' or '='.

Stephen