jobReference feature added

src/jio/features/jobReference.js

+/*jslint indent: 2, maxlen: 80, sloppy: true, unparam: true */
+/*global ReferenceArray */
+
+function enableJobReference(jio, shared, options) {
+
+  // creates
+  // - shared.jobs Object Array
+
+  // uses 'job', 'jobEnd' events
+
+  shared.jobs = [];
+
+  var job_references = new ReferenceArray(shared.jobs);
+
+  shared.on('job', function (param) {
+    job_references.put(param);
+  });
+
+  shared.on('jobEnd', function (param) {
+    job_references.remove(param);
+  });
+}