in `cc_binary_string()`, ticket #300 (#5 & #6), props Andre Maute;
add other checks for length on processing encoding mode
PDF417: fix out-of-bounds crash on overrunning string and codeword
buffers by tripling size (convert to `short` instead of `int` to
guard against too much stack), ticket #300 (#7 & #10), props Andre
Maute; (TODO: add some checks instead to bail out earlier?)
CODEONE: fix looping on latch crash in `c1_encode()`, ticket #300 (#8),
props Andre Maute
CODABLOCKF: fix crash on negative overflow of `columns` (`option_2`),
ticket #300 (#9), props Andre Maute
library: add `debug_print_escape()` helper for ZINT_DEBUG_PRINT
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
Rename barcode funcs to same as BARCODE_XXX name
library: barcode funcs array for dispatch, used for ZBarcode_ValidID() also
general: change is_sane() comparison to nonzero from ZINT_ERROR_INVALID_OPTION
MAILMARK: fuller error messages
CODABAR: add option to show check character in HRT
zint.h: use 0xNNNN for OR-able defines
GUI: add guard descent height reset button, add Zint version to window title,
static get_zint_version() method, use QStringLiteral (QSL shorthand),
use SIGNAL(toggled()), add errtxt "popup" and status bar, add icons,
add saveAs shortcut, add main menu, context menus and actions, add help,
reset_view() -> reset_colours(), add copy to clipboard as EMF/GIF/PNG/TIF,
lessen triggering of update_preview(), shorten names of getters/setters,
simplify/shorten some update_preview() logic in switch,
CODEONE disable structapp for Version S
qzint.cpp: add on_errored signal, add missing getters, add test
GRIDMATRIX, MAXICODE, MICROPDF417, PDF417, QRCODE, ULTRA
DOTCODE: use pre-calculated generator poly coeffs in Reed-Solomon for
performance improvement
PDF417/MICROPDF417: use common routine pdf417_initial()
GUI: code lines <= 118, shorthand widget_obj(),
shorten calling upcean_addon_gap(), upcean_guard_descent()
various backend: var name debug -> debug_print
