Hi Chuck, hi all,

Attached to this message is a draft patch to complete this idea.  It
should address the issue of including warnings, errors, and messages in
output.

It uses the “evaluate” R package, originally created for the knitr
literate programming system, to do most of the heavy lifting, and
includes a new mechanism to load this package into babel sessions (and
to prompt the user to install it from CRAN, if not already installed).

It does not yet address Chuck’s first issue of remote sessions, just
because I haven’t had time to look at it in detail (but I still think it
should be easy, based on the code sample/hint that Chuck gave).

What do you think of the approach broadly?