from ZXing (props Alex Geller) - about 25-60% slower depending on
data & stack heavy but does improve some outcomes when FNC1s
present (GS1_MODE or manual) although not much else it appears
(the previous algorithm was very good), but has a logical clarity
the other lacked - funcs `c128_dxsmooth()` etc shared with
CODE16K now moved there and renamed as `c16k_`;
also fix extended char latching when exactly 4 extended chars
at end
also manual code set switching now honoured exactly even if
immediate shift required;
manual: make explicit that AI "(00)" and "(01)" prefixes added by
Zint are HRT-only
general: add `extern "C"` wrappers to a few header files
as to fully comply with BSD license (for why Library GPL 2+ not
compatible see https://opensource.stackexchange.com/a/6701),
~3% slower (maybe), +~6K extra in data
(gb18030.c, gb2313.c & sjis.c removed, mapping .TXT files moved
to backend/tools/data & extra ones added, 2 new PHP generators)
GUI: CODE39/EXCODE39: show/hide HIBC check digit option in addition
to enable/disable (less confusing)
CLI: batch: pedantic check for EOF using intChar in newline fgetc()
loop
test_args.c: don't use WIFEXITED(), WEXITSTATUS() on Windows
manual: lessen some copy/paste verbiage by referring back, other
small tweaks/typos
GRIDMATRIX, HANXIN, MAXICODE, MICROPDF417, PDF417, QRCODE, RMQR, ULTRA
RMQR: fix ECI encoding (wrong bit length for indicator)
MICROQR: check versions M1 and M2 for allowed characters so as to give
better error messages
DOTCODE: some small optimizations
common.c: add is_chr(), segs_length(), segs_cpy()
CODEONE/CODE128/DOTCODE/GRIDMATRIX/HANXIN/MAXICODE/QRCODE/ULTRA: add
namespace prefixes to static funcs/data
includes: use Z_ prefix, unuse double underscore prefixes (guard defines)
manual.txt: compress some tables using double/treble column sets
