RMQR: update to new draft ISO/IEC JTC1/SC31N000 (Draft 2019-6-24);
allow for righthand vertical timing pattern in populate_grid()
ULTRA: update max size and min cols based on BWIPP 2021-07-14 update
backend_tcl/zint_tcl.dsp: use /MD instead of /MT for tcl lib compat;
change include/lib path to more standard one
manual.txt: highlight that rMQR is still in development
GUI: use cross-platform smaller font func instead of explicit values for notes
bmp/emf/ps.c: allow for foreground colour in ULTRA
bmp/gif/pcx.c: allow for BARCODE_STDOUT (fflush/fclose)
emf.c: hexagon rotation field not used; dont't use float index in font loop; Windows stdout binary mode
png.c: remove unused 8-bit; simplify libpng error handling and fclose outfile on error
ps.c: fix buffer overflow on colour_to_pscolor() CMYK
tif.c: fix BLACKISZERO indexes
CODE39: simplify check digit setting
reedsol.c: rs_uint_init_gf() log/alog tables must be zeroed
ZBarcode_Encode: debug: fix access out-of-bounds on non-NUL-terminated source if length < 10
manual.txt/zint.h: document NUL-terminated strings
tests: cover further cases for output (bmp/emf/etc), eci/gb18030/gb2312/sjis, reedsol, AZTEC, CODE39
test_file_unreadable cannot be implemented easily, as files are always
readable by their owner on windows. While `_chmod` is available in the POSIX
compatibility function set, it cannot be used to take away read permissions,
either.
While here, move functional code out of any assert statements. It shall be
executed even when the assertions are disabled
PLESSEY: add options NCR weighted mod-10, hide check digit(s) in HRT
test suite: now runnable under MSVC 2019, 2017, 2015, MinGW/MSYS
win32/README: update with MSVC 2019 and CMake instructions
