Issue: Fails to export dam node with exception

The new JCR-browser app throws an excpetion, when a user tries to export a node from the dam workspace. (stack-trace)

Since this worked on 6.2.2 with the "old" browser, the new browser also should support it. Note that dam nodes must be exported as XML!

Missing option: export format always YAML

On the old JCR-browser, when exporting a node without a binary, the user can decide whether he wants YAML or XML.
The new JCR-browser automatically exports always YAML.
The new app should allow to choose the format (as the old app did).