[Rd] Links to non-vignette documentation

[hadley wickham]

> >> Is there anyway to have my pdf documentation listed under vignettes
> >> other than making it a sweave file?
>
> No, a vignette is regarded as an Sweave file.

It would be useful if there was a mechanism to allow arbitrary pdf
files to be included as vignettes.  There are many other ways to
include R code/output in pdf files other than through Sweave.

> I just tried this by adding inst/doc/foo.pdf to windlgs.  If there is an
> pdf file but no .[RS]nw vignettes, the index is fairly useless but
> browsing is available.
>
> > I don't know if the sentence about pointers being created is true otherwise.
>
> It seems to be.

A link to the directory where the pdf is located, only available in
the html version of help, rather stretches the definition of a
pointer.

Hadley