Ported r2696 from ZXing

Original commit message: "Fix two other AIOOBE from pure barcode mode,
update javadoc"
Ported r2697 from ZXing

Original commit message: "Update other tests to reflect better
performance"
Ported r2700 from ZXing

Original commit message: "For consistency, name 'pdf417' image directory
as 'pdf417-1'
Ported r2705 from ZXing

Original commit message: "Minor inspection cleanup"