Use result in db instead of ipc

src/tasks.js

@@ -3,6 +3,7 @@
 exports = module.exports = {
     setProgress: setProgress,
     getProgress: getProgress,
+    clearProgress: clearProgress,
 
     stopTask: stopTask,
 
@@ -70,6 +71,13 @@ function getProgress(id, callback) {
     });
 }
 
+function clearProgress(id, callback) {
+    assert.strictEqual(typeof id, 'string');
+    assert.strictEqual(typeof callback, 'function');
+
+    setProgress(id, { percent: 0, message: 'Starting', result: '', errorMessage: '' }, callback);
+}
+
 function stopTask(id, auditSource, callback) {
     assert.strictEqual(typeof id, 'string');
     assert.strictEqual(typeof auditSource, 'object');