Let *tex handle figure placement as per Jeremy's suggestion.
Merged chapters 1 and 2 as per Jeremy's suggestion.  Move a few
smaller sections around so the document flows better.

Working on threats to validity next.
Updated ToC, moved some background around, minor edits.
More edits, fixed up motivation and such.
Moved background section to its own section.
Added reference to software engineering book, updated introduction and conclusions.
Updated to include some of Kevin's suggestions.
Re-worded some of the later sections of chapter 1.
More grammatical checks and edits.
More grammatical edits.
More edits to the document in an attempt to remove filler words and other unnecessities (new word).