These are things that need to be done to ispell but which there wasn't time
to complete for version 4.0.  Contributions of code to implement these
things would be greatly appreciated.

* Clean up the configuration.  In particular, remove the generic USG/BSD
  checks and add checks for individual missing features instead. 
* Investigate if the systems where TIOCGWINSZ is broken, TIOCGSIZE (and
  struct ttysize) are available and work. 
* Properly document options for ispell in usage string.
* Add long options.
* Add more words to dictionary, perhaps making several separate
  dictionaries (e.g. one with uncommon technical words and abbreviations). 
* When typing a correction in the emacs interface, it should check that
  word for spelling errors as well, instead of requiring the user to
  explicitly invoke ispell again. 
* Better overall elisp interface.  In particular, it would be nice to be
  able to switch buffers and edit, then come back to the minibuffer and
  finish commands. 
