document-list improvements (#1169)

* #1167 document-list improvements

- allow setting custom root path
- document-list module now re-exports datatable module (no need
importing it separately if document-list is already used)
- documentation updates and fixes

* readme updates and unit test

ng2-components/ng2-alfresco-documentlist/index.ts

@@ -80,6 +80,7 @@ export const DOCUMENT_LIST_PROVIDERS: any[] = [
         ...DOCUMENT_LIST_PROVIDERS
     ],
     exports: [
+        DataTableModule,
         ...DOCUMENT_LIST_DIRECTIVES
     ]
 })