`options_3`, allowing forcing of Base 256 or C40 mode a la BWIPP
for initial no. of characters specified in `option_1`, with 0
meaning all (CLI "--dmb256=" and "--dmc40=", GUI also (apart
from MAILMARK_2D, which may be added later);
export masks `DM_B256_C40_START_MASK` & `DM_SQUARE_DMRE_MASK` in
"zint.h"
ZBarcode_Encode_File: report filename (possibly truncated) in error
message on failed open
GUI: uniquify some accelerators and add some child widget getter
helpers to "mainwindow.cpp"
backend/DEVELOPER -> backend/README, with some expansion
debian/copyright: a few more fixes
BWIPP/pandoc: update to latest
tests/fuzz: adjust for new DATAMATRIX options
template, props Dmitry Smirnov (ticket #147, props John Crisp);
TODO: enable building with the GS1 Syntax Engine;
this involved auditing copyrights which prompted the next item
re "tif.c" and will prompt the next next item "pdf417.c"
tif.c: replaced LZW compression with tree-based one due to
"tif_lzw.h"'s original BSD-TAHOE license which has the equivalent
of the "advertising clause", new implementation (which is much
faster anyway) props Harald Kuhr and Bob Montgomery
pdf417.c: TODO: Replace all code adapted from "pdf417.frm" as it
was released under GPL v2.0 or later
pdf417.h: replace unnecessary "pdf417.frm" references with ISO/IEC
standard as 1st step re above, some expanded comments
general: Codablock-F -> Codablock F (i.e. lose hyphen)
cmake: frontend/frontend_qt: go back to only setting RPATH on macOS
as not Debian compatible and it seems it's not a good idea on
Linux anyway; TODO: check BSD + other Unixes
CLI/GUI: make "--verbose" option official and document
tools/gen_eci_sb_h.php/gen_eci_mb_h.php: add SPDX Unicode-3.0;
update haible.de/bruno tarball info - "GB18030.TXT" no longer in
"jdk-1.4.2/" so mention "libiconv-1.11/" version instead (same)
general: add various SPDXs and normalize some Copyrights
reedsol.c: malloced `logt`/`alog` tables int -> short (slight
performance improvement)
aztec.c: add copyrights, some code fiddling
BWIPP: update to latest
