[R] barplot - change width of bar outline

[Rolf Turner]

Ummmm, addendum/correction.  Forget what I said about cross-hatching.
Without realizing it, I was looking at my own personal/local version of
barplot.default, into which I'd built a cross-hatching capability.  The 
``real''
barplot.default doesn't have such a capability.  Apparently R Core doesn't
approve of cross-hatching.

Anyhow, Mark Schwartz's workaround seems to accomplish what you want
without your having to do any code-hacking.

You should probably re-set par(lwd=1) after you've drawn your barplot()
irrespective of wanting to do any shading, to avoid surprises with line 
widths
in later graphics.

     cheers,

         Rolf Turner