QRCODE: use stricter interpretation of ZINT_FULL_MULTIBYTE, excluding
certain trailing bytes
libzint: fix some confusing error messages introduced by segment stuff
general: new escape chars \U, \d and \o
backend_qt: fudge rendering of border rectangles due to scaling/translation
rounding errors TODO: better fudge
GUI: foreground/background colours -> text boxes and icon buttons, add swap
button, independently movable picker (NULL parent), preview colour changes,
preview Data Window changes, add clear data (del) buttons, add zap button
and Factory Reset menu option, various other fixes
libzint: remove STATIC_UNLESS_ZINT_TEST, use wrappers
CMake: add find package QtSvg, remove QtXml
manual: split symbology and general specs and sort, move DAFT to 4-state,
UPC/EAN -> EAN/UPC, DataBar -> GS1 DataBar always, expand MAILMARK info,
various other fiddlings
man page: options or -> |, expand MSI Plessey check digit options
README.linux: add packages info
license: add SPDX-License-Identifier to touched 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
