Ported r2577 from ZXing

Original commit message: "Aztec encoder"
Ported r2581 from ZXing

Orginal commit message: "Various changes from IJ12.1 inspections"
Ported r2582 from ZXing

Original commit message: "Missed a test improvement"
Ported r2583 from ZXing

Original commit message: "Issue 1638 support for several URLs in contact
info, and some incidental test cleanup too"