Add multiple segments support for AZTEC, CODEONE, DATAMATRIX, DOTCODE,

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

backend/gs1.h

@@ -2,7 +2,7 @@
 
 /*
     libzint - the open source barcode library
-    Copyright (C) 2009 - 2020 Robin Stuart <rstuart114@gmail.com>
+    Copyright (C) 2009-2022 Robin Stuart <rstuart114@gmail.com>
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -29,9 +29,8 @@
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
  */
-/* vim: set ts=4 sw=4 et : */
-#ifndef __GS1_H
-#define __GS1_H
+#ifndef Z_GS1_H
+#define Z_GS1_H
 
 #ifdef __cplusplus
 extern "C" {
@@ -45,4 +44,5 @@ INTERNAL char gs1_check_digit(const unsigned char source[], const int src_len);
 }
 #endif /* __cplusplus */
 
-#endif /* __GS1_H */
+/* vim: set ts=4 sw=4 et : */
+#endif /* Z_GS1_H */