[Groff] italic correction for non-slanted files

[Werner LEMBERG]

I wonder whether we should add italic correction values for
non-slanted fonts to the metric files...  At a first glance, I can't
see any negative side effects.  The benefit would be that the real
horizontal bounding box values would be available.

Reason for asking is a problem with grohtml: For example, the word
`groff' typeset with Times-Roman is cropped too much because the
advance width of the final `f' is about 15% less than the real width
taken from the bounding box.

Here the entry from the current TR font definition file:

  f    333,683            2    0146    -- f

Here the entry if created with `-i 0' added to the command line of
afmtodit:

  f   333,683,0,50,-20    2    0146    -- f
                ^^
     right bearing
                   ^^^
                   left bearing

The only affected escapes would be `\/' and `\,' which will do
something for non-slanted fonts also.


    Werner