[l2h] href'ing source files

[Graham Gough]

I often create documents in one directory and then copy the output
from l2h somewhere else to appear on the web. This means that I always
end up with a broken link to the latex source in the `About this
document' section. Could you please add a flag to turn off the
href'ing of the source file? At the moment I have just commented out
the line

  if (-f "../$argv") { $argv = &make_href ("../$argv", $argv, ); }

but it would be nice to have a cleaner solution which was more
customisable per document 

Thanks

Graham