Split some lines that began with one sentence and then continued with
another so that each sentence has its own line as per 'roff guidelines.
Change the continuation lines in the files and environment sections
to begin with <backslash><space><tab> instead of just <tab>, again to
meet the guidelines (don't begin lines with whitespace). This had a
side-effect of suppressing some space insertion for justifying right
margin of right-hand column on some of the lines. That hadn't looked
very good anyway.
Add new file 'usagehlp' to the files section.
Also add previously unmentioned Guidebook[.txt], but it's hard to
explain why it probably won't be present....
Update the bones file entry.
'cmdhelp' isn't used anymore. Should it be moved to outdated/dat and
the Makefile install steps be updated to stop bothering with it?
7e33da788c