porthelp modifications

porthelp modifications
- keep boolean and valued option sections together
- be more consistent in use of terms "graphical port"
  and "graphical interface" in the document (use the
  latter where noticed)
- don't mention options available in other ports so
  much since this document is not a general
  document.
- move the numeric keypad stuff to the end. It seems
  to assume number_pad on. So I stated that it does.
  (Many players never play with number_pad on, and
   I'm one of them. I'm not sure of the merit in having
   the section in here at all, since it exists in the
   Guidebook doesn't it?)  How accurate is the text
   that is there if you aren't in number_pad mode?