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
and `out_colour_get_cmyk()`, to lessen chances of rounding
errors (in particular for VC6)
test_large: fix regression in change to test for formatting
`uint64_t` for `printf()`
win32/README: update MinGW/MSYS Qt version
test `ferror()` also in `fm_err()` if `err` zero and file
NetBSD: add instructions and some workarounds (`getopt_long_only()`
in particular)
qzint: check `__GNUC__` version for "-Wstringop-truncation"
suppression
outputting to in-memory buffer `symbol->memfile` instead of to
file `symbol->outfile`, ticket #301
Add "README.clang-tidy" and ".clang-tidy" options file
Suppress some warnings
