Zebra v1.0.0-alpha.2

Zebra's latest alpha brings multiple reliability and stability improvements for node startup, node shutdown, and long-running syncs.

Some notable changes include:

Added

• Asynchronous Groth16 verification (#830)
• Security disclosure principles (#1650)

Changed

• Document that connect_isolated only works on mainnet (#1693)
• Document the impact of the redjubjub channel bound (#1682)
• Log when the syncer awaits peer readiness (#1714)

Fixed

• Fix shutdown panics (#1637)
• Add hints to port conflict and lock file panics (#1535)
• Perform DNS seeder lookups concurrently, and add timeouts (#1662)
• Avoid buffer slot leaks in the Inbound service (#1620)
• Avoid a buffer slot leak by removing CallAllUnordered (#1705)
• Avoid future buffer slot leaks in ChainVerifier (#1700)
• Limit inbound download and verify queue (#1622)
• Increase a tower-batch queue bound (#1691)
• Fix a f64::NAN metrics sentinel (#1642)
• Actually use VerifyCheckpointError::CommitFinalized (#1706)