Add option in communication config to choose which Whisper client to use.
Because Parity’s implementation of Whisper is not compatible with Whisper v6, and therefore web3.js in its current form, the following changes have been made:
1. remove any functionality associated with launching a Parity Whisper process.
2. Warn the user when the Parity Whisper client has been opted for in the communication config.
3. Return an error for API calls when Parity Whisper client has been opted for in the communication config.
4. Update Cockpit’s Communication module to show errors returned from API calls.
5. Update the messaging configuration documentation for the new communication client option.
1. get rid of the whisper layer and handle everything in the communication layer
2. Create a gethWhisper and a parityWhisper plugin that has the same files as packages/embark/src/lib/modules/geth, except with a whisperClient instead of gethClient, and will include most of https://github.com/embark-framework/embark/blob/master/packages/plugins/whisper/src/index.js.
3. Get rid of any whisper registration in geth.
4. In the whisperGeth and whisperParity plugins, modify the request for communication:node:register, to end up calling `startWhisperNode`