Hashgraph 4.0.0

Release 4.0.0 Address and Signatory objects completely replace Account Object.

Version 4.0.0 contains significant breaking changes from the 3.x releases. This version eliminates the Account object. The original account object was a fusion of an Address identifying an Hedera account and on or more Ed25519 private signing keys. This architecture mistake needlessly restricted use of the library and necessitated odd workarounds such as adding extra keys to the Payer account to accommodate for signing transactions creating files and contracts with their own separate administrative keys. To fix this mistake the Account object was split into two parts: the Address and Signatory. The address object already exists in the library and identifies accounts, files and contracts within the network. The new object, Signatory, was created to hold private signing keys (Only Ed25519 supported at this time) or hold a reference to a callback function that can sign a given transaction. Signatories are read-only once created but can be merged together representing a bag of signing keys. The Context now contains a Signatory property along side the Payer property. Note: any key held in the context will be asked to sign all transactions, including those just receiving a follow-up record request. Therefore, it is recommended to leverage the Signatory objects visible elsewhere in the API for task specific purposes. For example, the File Create parameter object has a new Signatory property as well. It is recommended to place any necessary file signing keys inside the create parameters signatory instead of the global signatory for the client’s context when creating the file.

Additionally, 4.0.0 fixes the lexical ordering of account addresses throughout the library. The order in Account and Gateway constructors is now (SHARD).(REALM).(NUMBER). The 3.x releases had the parameters out of conventional order, having the realm number appear in constructors before the shard number.