* refactor address generation code into libwallet, bool to flag whether to include proof, add sender address in init_send_tx
* rustfmt
* require payment proof addr as part of init_tx
* rustfmt
* store payment proof on sender transaction side
* rustfmt
* change sig to ed25519 sig
* rustfmt
* add message creation and signature
* rustfmt
* add payment proof verification function
* rustfmt
* validate proof on sender side, store proof
* rustfmt
* fix json tests
* fixes and updates to tests
* added API functions for converting and retrieving proof addresses
* rustfmt
* add payment proof to init_send_tx example
* rustfmt
* incorrect comment
