Spacing with Font Roboto

[Bob Tennent]

    using the original TTF fonts instead of converting them to OTF

  Agreed that using original fonts sounds better in general.

  I don't know why Bob changed the setup, but I doubt he did it
  lightly. Perhaps he can advise.

otftotfm works more reliably with otf fonts. I can't recall
what probems arose with the ttf roboto set but in the future
I'll try harder to avoid ttf-to-otf conversions.

BTW, roboto.sty uses font filenames; notice the 

Extension = .otf 

in \defaultfontfeatures.

Bob T.