ticket #300, props Andre Maute;
fix 4-layer compact block max (76 -> 64);
fix encoding of byte-blocks > 11-bit limit
library: fix 21-bit Unicode conversion in `escape_char_process()`;
fix restricting escaped data length by using de-escaped length to
check (`escape_char_process()` adapted to do length only calc
also)
replace double-slash comments with old-skool slash asterisk ones;
define uint16_t etc for Windows ourselves and remove ms_stdint.h &
stdint_msvc.h as no longer used;
(backend (excepting test suite) now C89 compatible)
LICENSE: move from backend to root and move COPYING to frontend, with
copies in frontend_qt & backend_qt, so in where it applies;
add LICENSE section from manual to root README
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