Add option to set random seed for deterministic behavior

Bump version to 1.6

lib/options.h

@@ -2,12 +2,16 @@
 #define _OPTIONS_H 1
 
 #include <stdint.h>
+#include <stdbool.h>
 
 typedef uint8_t rgb_color_t[3];
+typedef unsigned int rand_seed_t;
 
 typedef struct mazeoptions {
     rgb_color_t wall_color;
     rgb_color_t background_color;
+    rand_seed_t seed;
+    bool seed_set;
 } mazeoptions_t;
 
 #endif // !def(_OPTIONS_H)