Don't need NULL character for stringWithCharacters. Fixes #50
Add ZXDataMatrixEncoder.h to the project. Fixes #52
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"
Ported r2585 from ZXing

Original commit message: "Avoid stack overflow in some odd case in
multiple barcode detection, and don't use multiple threads for one image
on the command line"
Ported r2586 from ZXing

Original commit message: "Make sure strings with a space aren't
considered a URI"
Merge remote-tracking branch 'upstream/master'