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
UTF-16LE, GBK, separate GB18030, UTF-32BE, UTF-32LE
add examples to tests for DATAMATRIX, HANXIN, QRCODE
HANXIN: Remove alternating filler in function information;
GB 18030 now ECI 32 (previously used ECI 29);
fix gate-posts on codeword limits
use new ZXing-C++ HanXin detector (diagnostics2 branch) for tests
check against ISO/IEC 20830:2021 (no substantive changes)
backend_tcl: update ECIs; NOTE: changed names "unicode" -> "utf-16be",
"euc-cn" -> "gb2312"
GRIDMATRIX/HANXIN/QRCODE/RMQR: warn if auto-conversion (i.e. no ECI given)
occurs to resp. specialized char sets (GB 2312/GB 18030/Shift JIS)
DMATAMATRIX: fix look ahead BASE256 use of dm_text_sp_cnt() on switching;
simplify dm_add_tail()
GUI: check suffixes on save so don't go into error state;
use native path for Save As clipboard message
CODE128: use gs1_check_digit() for NVE18 and EAN14
