Bump ZBar to version 0.21
0.21:
- zbarcam-qt: allow selecting codes via GUI interface
- When both enabled, ISBN-13 has precedence over ISBN-10
- ZBar is now using Travis CI for continuous integration tests
- Convert INSTALL and README to markdown and update them
- Improve ZBar testing code and make easier to run the tests
- Fix build with Clang
- Add simple dbus IPC API to zbarcam.
- zbarimg: display only the compiled symbologies
- v4l2: make ZBar build and run on Kernels < 3.16
- configure.ac: The pdf417 code is incomplete. Warn about that
- Add Debian packaging and Travis CI configuration
- Add barcode examples for different supported symbologies
- Several improvements at the building system
- Add support for SQ code symbology
- v4l2: add fallback for systems without v4l2_ext_controls which field
- v4l2: use device_caps instead of capabilities
- v4l2: make v4l2_request_buffers() more generic
- release video buffers after probing and request them again when needed
- Ignore ENOTTY errors when calling VIDIOC_S_CROP
- doc/Makefile.am.inc: clean html generated files
- Add --disable-doc configure option to disable building docs
- Fix function protoype to be compatible with recent libjpeg
- Wrap logical not operations into parentheses
- INSTALL: warn that autoconf should be called before configure
- code128: fix error logic
- convert: ensure that it will not use a freed value
- zbar: use g_thread_new() instead of g_tread_create()
- zbargtk: add a missing break
- gtk/zbargtk: add a missing check if zbar->window is not null