Begun work on bignums; changed integer size to 64 bits

I'm fairly sure the size of a long int on my machines is 64 bit anyway, but for portability it needs to be explicit.

utils_src/tagvalcalc/tagvalcalc.c

@@ -1,9 +1,26 @@
 #include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TAGLENGTH 4
+
+struct dummy {
+  union {
+    char bytes[TAGLENGTH];  /* the tag (type) of this cell,
+                                   * considered as bytes */
+    uint32_t value;         /* the tag considered as a number */
+  } tag;
+};
 
 int main( int argc, char *argv[] ) {
+  struct dummy *b = malloc( sizeof( struct dummy));
+  struct dummy buffer = *b;
 
   for (int i = 1; i < argc; i++) {
-    printf( "%4.4s:\t%u\n", argv[i], (uint32_t)*argv[i]);
+
+    strncpy( &buffer.tag.bytes[0], argv[i], TAGLENGTH );
+
+    printf( "%4.4s:\t%d\n", argv[i], buffer.tag.value);
   }
 }