web service data parser should ignore XML tags

[embeepea]

So that it will correctly work with old-style data services that surround their responses with tags.

[embeepea]

Um, according to

https://github.com/multigraph/js-multigraph/blob/master/src/core/web_service_data.js#L222-L225

it appears that this is already implemented. So why did the example that Rich and I were looking at in his office today not work? Test by creating a data service that includes tags and check that Multigraph really works with it.