4.0.0-pre.1

• Implements new LazyOption type under unstable feature. Similar to Lazy but is optional to set a value. PR 444.
• Move type aliases and core types to near-sdk to avoid coupling. PR 415.
• Implements new Lazy type under the new unstable feature which is a lazily loaded storage value. PR 409.
• fix(promise): PromiseOrValue now correctly sets should_return flag correctly on serialization. PR 407.
• fix(tree_map): Correctly panic when range indices are exluded and start > end. PR 392.
• Implement FromStr for json types to allow calling .parse() to convert them.
  • ValidAccountId PR 391.
  • Base58CryptoHash PR 398.
  • Base58PublicKey PR 400.
• expose cur_block and genesis_config from RuntimeStandalone to configure simulation tests. PR 390.
• fix(simulator): failing with long chains. PR 385.
• Make block time configurable to sim contract tests. PR 378.
• Deprecate env::log in favour of env::log_str. The logs assume that the bytes are utf8, so this will be a cleaner interface to use. PR 366.
• Update syscall interface to no longer go through BLOCKCHAIN_INTERFACE. Instead uses near_sdk::sys which is under the unstable feature flag if needed. PR 417.
• Set up global allocator by default for WASM architectures. PR 429.
  • This removes the re-export of wee_alloc because if this feature is enabled, the allocator will already be set.
  • Deprecates setup_alloc! macro as this will be set up by default, as long as the wee_alloc feature is not specifically disabled. In this case, the allocator can be overridden to a custom one or set manually if intended.
• Update TreeMap iterator implementation to avoid unnecessary storage reads. PR 428.
• Update AccountId to be a newtype with merged functionality from ValidAccountId
  • Removes ValidAccountId to avoid having multiple types for account IDs
  • This type will have ValidAccountId's JSON (de)serialization and the borsh serialization will be equivalent to what it was previously
• Initializes default for BLOCKCHAIN_INTERFACE to avoid requiring to initialize testing environment for tests that don't require custom blockchain interface configuration
  • This default only affects outside of wasm32 environments and is optional/backwards compatible
• Deprecates env::block_index and replaces it with env::block_height for more consistent naming
• Updates internal NFT traits to not move the underlying type for methods
  • This should not be a breaking change if using the impl macros, only if implementing manually
• Makes BLOCKCHAIN_INTERFACE a concrete type and no longer exports it.
  • If for testing you need this mocked blockchain, near_sdk::mock::with_mocked_blockchain can be used
  • near_sdk::env::take_blockchain_interface is removed, as this interface is no longer optional
  • removes BlockchainInterface trait, as this interface is only used in mocked contexts now
• Updates Gas type to be a newtype, which makes the API harder to misuse.
  • This also changes the JSON serialization of this type to a string, to avoid precision loss when deserializing in JavaScript
• PublicKey now utilizes Base58PublicKey instead of Vec<u8> directly PR 453. Usage of Base58PublicKey is deprecated
• Expose Receipt and respective VmActions in mocked contexts through replacing with a local interface and types.