Add Data Matrix Rectangular Extension (DMRE) in regular distribution

- add define "DM_DMRE	101" to zint.h as option_3 value
- add option "-dmre" to command line
- add ckeckbutton "Activate DMRE in automatic mode" to qzint
- make dmatrix.c/dmatrix.h aware of option_3 value DM_DMRE and include DMRE in automatic mode
- Use version 2.5 everywere (as already started by Robin)
- common test case for DMRE in automatic mode is numeric input data with 48 digits, which should lead to a symbol of size 8x64

backend/zint.h

@@ -202,6 +202,7 @@ extern "C" {
 #define SJIS_MODE	4
 
 #define DM_SQUARE	100
+#define DM_DMRE	101
 
 #define ZINT_WARN_INVALID_OPTION	2
 #define ZINT_ERROR_TOO_LONG		5