Whisper rpc types

[coffeepots]

Small PR that:

• Updates the whisper types and FilterOptions to be optional
• Removs the duplicated WhisperIdentity from rpc_types.nim as it's already present in eth_common.eth_types.
• Adds WhisperFilterOptions
• Updates the signature for shh_newFilter to use WhisperFilterOptions rather than the eth FilterOptions

[zah]

@kdeme, Ryan (@coffeepots) wasn't aware that you'll be also working on this. He'll be happy to leave the rest of the integration work to you.

[coffeepots]

Yes, these changes are just updates to data structures really. In particular shh_newFilter was incorrect so that had to change anyway.

[kdeme]

OK, that's fine.

I was however planning of changing the RPC calls to the list here: https://github.com/ethereum/go-ethereum/wiki/Whisper-v6-RPC-API

I assumed that this is the latest version and that https://github.com/ethereum/wiki/wiki/JSON-RPC is not up to date with regards to Whisper v6.

Or where should I be looking for the latest correct Whisper RPC API?

There is this EIP in the making, but Whisper is not included there.

[zah]

The v6 RPCs would indeed be the most useful ones. It's what the Status app relies on.

[coffeepots]

Yes I was working with https://github.com/ethereum/wiki/wiki/JSON-RPC so it looks like all of the RPC stubs for whisper are out of date now.