[tex-eplain] Hyperlinks in Eplain

[Karl Berry]

    This patch seems to do this.  

Sorry for coming in late on this, but I don't think there should be a
warning at all.  The code should just adapt to whatever is being run.
Like \usepackage{graphicx} -- if pdf output, pdftex is selected as the
driver, if dvi output, dvips.  Am I misunderstanding?

    check `\ifx\pdfoutput\relax' is really necessary --

It is what ifpdf.sty does.

In fact, I think eplain.tex should include ifpdf.sty (it works in plain
TeX).  I'll try to arrange for that, in some future day when I actually
have 20 minutes to upload the Eplain sources.  And then your code should
just use \ifpdf

Thanks,
k