This contains some changes of phrasing in the documentation, plus a lot of
unnecessarily picky places where I added an extra space after a full stop.
I resisted the temptation to change variant spellings, however.  I got as
far as not understanding the insert-ids style, so it's not finished.  I'll
have another go later.

There are two functional changes:  a typo in _jobs, and I final got fed up
with the integer builtin not taking `-i base'.

There have been various small changes, with others suggested, in the last
week, so I'll produce pre-4 when I've finished with the docs and then leave
it for a few days.