Customisation of global actions (folders and documents)

- support for registering custom global actions (folders, documents)
- documentation update with code samples and pictures

refs #9

ng2-components/ng2-alfresco-documentlist/src/services/document-actions.service.ts

@@ -35,6 +35,13 @@ export class DocumentActionsService {
         return null;
     }
 
+    setHandler(key: string, handler: ContentActionHandler): void {
+        if (key) {
+            let lkey = key.toLowerCase();
+            this.handlers[lkey] = handler;
+        }
+    }
+
     private setupActionHandlers() {
         this.handlers['download'] = this.download.bind(this);