Clean up handling of Abbreviations.

1) Handle Alan's abbreviation list correctly.

2) Allow words in known-upper.lst to be considered abbreviations.
(The name known-upper.lst is a bit misleading as it is really a list
of possible candidates.)
Clean up handling of Abbreviations/Upper/Proper Names/Contractions.

In particular make sure "'s" forms of abbreviations are marked as such
and make sure all forms of OK, and AWAL are marked as normal words.