This is a small portion of zxing, including only what's required
to generate QR codes. There are no modifications.
We've added a build.xml for ant.

Pulled from https://github.com/zxing/zxing on Jan. 4, 2016,
rev 4e3abafe3008e02695f894eccf05f8257fca4ee9 dated Dec. 9, 2015.
