Add some docs clarifying where changes come from

[plivesey]

https://github.com/linkedin/RocketData/issues/31

e.g. For network calls and setData, the delegate is not called. The delegate is only called for consistency changes.

[katalisha]

+1 for this

I was expecting methods like append/insert in the collectionDataProvider to call the delegate but they don't seem to. Is that right?

In the sample app the dataProvider.append([message]) isn't triggering the delegate for me.