[ADF-571] upload feature rework (#1922)

* upload feature rework

lots of improvements for upload dialog and underlying services

* readme update

- readme cleanup
- remove some old comments from code
- update readme with new events for Upload Service

* restore prerequisites section in readme

ng2-components/ng2-alfresco-upload/src/events/file.event.ts

@@ -0,0 +1,36 @@
+/*!
+ * @license
+ * Copyright 2016 Alfresco Software, Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { FileModel, FileUploadStatus } from '../models/file.model';
+
+export class FileUploadEvent {
+
+    constructor(
+        public readonly file: FileModel,
+        public readonly status: FileUploadStatus = FileUploadStatus.Pending,
+        public readonly error: any = null) {
+    }
+
+}
+
+export class FileUploadCompleteEvent extends FileUploadEvent {
+
+    constructor(file: FileModel, public totalComplete: number = 0) {
+        super(file, FileUploadStatus.Complete);
+    }
+
+}