add replay functionality

common/Util.js

@@ -152,7 +152,19 @@ function coordByTileIdx(info, tileIdx) {
   }
 }
 
+const hash = (str) => {
+  let hash = 0
+
+  for (let i = 0; i < str.length; i++) {
+    let chr = str.charCodeAt(i);
+    hash = ((hash << 5) - hash) + chr;
+    hash |= 0; // Convert to 32bit integer
+  }
+  return hash;
+}
+
 export default {
+  hash,
   uniqId,
   randomInt,
   choice,