send human-identifiable info in the data blob so consumers can record a useful reference to the campaign

Currently the plugin uses unfakeable data (first payout address if I remember correctly) to create the pledge transaction label. However, that's not really helpful without some reference to what that address is.

As an alternative, if the data blob sends across two pieces of information - title and URL, then one or both of those should be good enough as a human-readable reference.

Issues to handle:

1. Make sure sending additional data in the blob isn't going to break anything (it shouldn't)
2. Plugin would need to be updated to make use of the new data. Will make an issue for that if #1 (closed) can be confirmed.