Bringing Halo 2 to Zcash

As the first implementation of Halo within Zcash, this would serve as a catalyst for Zcash user confidence and scalability,

New Release 4.2.0

New release 4.2.0 removes the zcashd dependency upon libsodium for ed25519 signature checks and instead uses the Rust implementation in

New Release 4.1.1

This is a hotfix release that addresses a performance regression in v4.1.0. It is recommended that either v4.0.0 or this