whitespace changes, which don't influence the layout of result manpage at all,
but also add -H to SYNOPSIS and state sort(1) appeared in v5, not v6 of
AT&T Unix.
remove TMPDIR stuff - it no longer applies, at least for now
move the note about link/unlink from BUGS to NOTES
add note about trailing record separator and lack of restriction on
line length or allowed bytes
- keep the case consistent between the actual name and what's referenced.
e.g, if it's `foo', don't use '.Nm Foo' at the start of a sentence.
- remove unnecessary `.Nm foo' after the first occurrence (except for
using `.Nm ""' if there's stuff following, or for the 2nd and so on
occurrences in a SYNOPSIS
- use Sx, Ic, Li, Em, Sq, and Xr as appropriate
