Added abstract.  Made grammar/style changes.

We still have lots of ?? symbols for Figures, citations, and tables, so
we need to clean those up.  Otherwise, just take a look at the abstract
and make it sound however you'd like.  I gave it a first stab.  I made
grammar/style changes all over the document.  Just tried to cut down
lengthy sentences, especially when the presented material was a little
difficult to visualize.  Changed some words here and there to make it
more formal.  After you make some changes, I'll give it another pass
when I arrive in VA tomorrow.