GetFromReplica / Failure Considerations

[If this doesn't apply to LCB, please close!]

While differences in the SDKs' handling of failures, and use of GetFromReplica may need changing in API 3.0...
For now, we need to tighten up the code sample so that in each SDK page it addresses the same error conditions, and has the same return type [array], as the Java example - or if not possible, documents this SDK's return type (and perhaps why it differs).