teach <cntrl> and <print> about Latin-1 controls
latin1 is unsigned chars, not signed
calculate correct offsets for character props

The offsets were only correct up to about 0x3000.  Above that,
span extents were completely wrong.  Also, rather than trying to
keep the offset by relative means, all we really need to do is
look at how many entries there are in the @name_lines to see how
far off that is from the current codepoint.  This is much less
fragile.