Viewer enhancements and Viewer Dialog prototype (#2200)

* viewer dialog scaffold

* toolbar divider component

* simple error screen

* material module and tooltips

* show file name in the title

* improved settings, simple image viewer

* flex-based image viewer, minor fixes

* ability to switch between viewers

* single viewer for images

* remove MDL from the Viewer component

* remove hardcoded demo shell layout

remove harcoded assumptions on "header" and "main" elements

* rework text viewer, remove MDL dependency

* upgrade 'unknown format' view, remove MDL

* simplify media viewer layout

* simplify image viewer

* clean pdf viewer

* migrate pdf viewer styles to scss

* rewrite pdf viewer host styles in scss

* fix unit tests and cleanup layout

* file viewer service

* viewer dialog supports downloads if url provided

ng2-components/ng2-alfresco-viewer/src/components/viewer-dialog.settings.ts

@@ -0,0 +1,23 @@
+/*!
+ * @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.
+ */
+
+export interface ViewerDialogSettings {
+    fileUrl?: string;
+    fileMimeType?: string;
+    fileName?: string;
+    downloadUrl?: string;
+}