With the coinbase receiver daemon in place, when starting a Grin
server in mining mode, the miner will now ask the receiver for a
coinbase output. The output is then used to insert in a block when
successfully mined.
Beginning of a first pass at simple wallet functionalities so
Grin can be used to author transactions. We introduce a
receiving server, to be at least able to build coinbase outputs
that can be used by the mining daemon.
Present:
* Coinbase receiving API.
* Command to start the receiving server.
* Beginning of a transaction sending command.
* Improvements to the REST API abstractions to support the above.
Still to do:
* Change to the miner daemon to use the receiving server.
* A command line sender.
* API to receive any transaction (not just coinbase).
* A command line receiver.
Beyond that, HD derivation and seed generation are very simple
so far and almost certainly insecure. Just for testing for now.
