Instagram node

This is my attempt on the Instagram node. Current example is showing the query node. Comments are welcome. I'll squash commits once we get this work into a pullable state. Thanks

The pull request is now ready @knolleary .
Interesting. However, the fitbit app configuration calls it "Callback URL" though so you shouldn't change that one and I think we want to be consistent. Since oauth calls it the oauth callback I suspect that continuing to use callback for consistency makes most sense.

Luckily I don't think users pay too much attention to the text of the URL they are cutting and pasting *and* you can write the accurate field name in the configuration hint to make sure they know exactly which field it needs to be pasted into.