ZINT shared library Change License From GPL to BSD

From May 2013( ZINT Version 2.4.3),  ZINT shared library(aka libzint or the backend) is licensed under BSD 3,  So we can include ZINT library in own close source products or link against it from own software.

Please notice the frontends and Qt4-backend are still under GPL.

btw, the latest version on github is still 2.4.2, and the newer version is on SourceForge.

ZINT was originally developed by Robin Stuart and licensed under the terms of the GPL (Gnu
Public License). In 2013 Robin Stuart and all developers that contributed to the code agreed
to change the license to a less restrictive one - BSD-license.

Zint is a suite of programs to allow easy encoding of data in any of the wide range of public domain barcode standards and to allow integration of this capability into your own programs.

Zint supports over 50 formats barcode encoding:

Code 11, Standard Code 2 of 5, IATA Code 2 of 5, Industrial Code 2 of 5, Interleaved Code 2 of 5, Code 2 of 5 Data Logic, ITF-14, Deutche Post Leitcode, Deutche Post Identcode, UPC-A, UPC-E, EAN-2, EAN-5, EAN-8, EAN-13, UK Plessey, MSI Plessey, Telepen Alpha, Telepen Numeric, Code 39, Extended Code 39, Code 93, PZN, Code 23, LOGMARS, Codabar, Pharmacode, Code 128, EAN-128, NVE-18, Code 16k, PDF417, MicroPDF417, Two-Track Pharmacode, PostNet, PLANET, Australia Post 4-State Symbols, RM4SCC, USPS OneCode, GS1 DataBar, DataBar-14, DataBar Limited, DataBar Extended, DataBar Stacked,
Composite Symbology, Data Matrix, QR Code, Maxicode, Aztec Code, EAN-13, Micro QR, Korea Post Barcode, HIBC Code 128, HIBC Code 39, HIBC Data Matrix, HIBC PDF417, HIBC MicroPDF417, HIBC QR Code, HIBC Aztec Code, Japanese Postal Code, Code 49, Channel Code, Code One, Grid Matrix, FIM and Flattermarken.

reference,
http://sourceforge.net/p/zint/code/ci/master/tree/backend/LICENSE