Add compliant height, using ZINT_COMPLIANT_HEIGHT flag for back-compatibility

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

ChangeLog

@@ -27,6 +27,10 @@ Changes
 - Add Structured Append support for AZTEC, CODEONE, DATAMATRIX, DOTCODE,
   GRIDMATRIX, MAXICODE, MICROPDF417, PDF417, QRCODE, ULTRA
 - ULTRA: add revision 2 support (based on BWIPP 2021-09-28 update)
+- Add compliant height
+- GUI: add Menu, copy to clipboard EMF/GIF/PNG/TIF, errtxt bar and status bar,
+  icons (feathericons)
+- CODABAR: add show check digit option
 
 Bugs
 ----
@@ -41,7 +45,8 @@ Bugs
   platform variation (#204 ARM-Cortex crash)
 - raster/vector.c: use new stripf() func to workaround gcc 32-bit
   float variations
-- raster.c: Don't allow for text if scale < 1.0
+- raster.c: Don't add height offset for text if scale < 1.0 (as won't print)
+- ISBNX: fix not returning error number (warning) correctly
 
 
 Version 2.10.0 2021-08-14