[ADF-610] Upload button and DnD area should not upload hidden files and folders (#1908)

[ADF-610]  upload cleanup
- more strongly typing
- api improvements

* Upload cleanup and api improvements

- remove old unused settings (formFields variable)
- individual options for uploaded files (i.e. versioning)
- upload button and drag-and-drop area now set individual settings for file versioning

* exclude hidden files from upload

ng2-components/ng2-alfresco-upload/src/models/file.model.ts

@@ -72,3 +72,7 @@ export class FileModel {
         });
     }
 }
+
+export interface FileUploadOptions {
+    newVersion?: boolean;
+}