guarantee asynchronous execution for batch reads and write queues

lib/batch-read.js

@@ -8,6 +8,8 @@ If the result of IO or computation is requested while an identical request
 is already in progress, wait until the first one completes and provide its
 result to every routine that requested it.
 
+Asynchrony is guaranteed.
+
 ## Usage
 
 Provide:
@@ -51,11 +53,12 @@ module.exports = function (/* task */) {
             var args = Array.prototype.slice.call(arguments);
 
             //if (map[id] && map[id].length > 1) { console.log("BATCH-READ DID ITS JOB for [%s][%s]", task, id); }
-
-            map[id].forEach(function (h) {
-                h.apply(null, args);
+            setTimeout(function () {
+                map[id].forEach(function (h) {
+                    h.apply(null, args);
+                });
+                delete map[id];
             });
-            delete map[id];
         });
     };
 };