Automatic snapshot pre-release monthly-2021-04

Changes since last snapshot (monthly-2021-03)

Substrate changes

Runtime

• Add an INDEX to the Instance trait (#8555)
• Fix account ref-counting in session (#8538)
• Introduce OnSetCode type into system config trait. (#8496)
• Implement fungible::* for Balances (#8454)
• [pallet-staking] Refund unused weight for payout_stakers (#8458)
• Make the number of nominations configurable (#8368)
• Add tracing logic in pallet macro for hooks and dispatchables (#8305)
• contracts: Update deduct block when a contract is excempted (#8418)
• Decouple Staking and Election - Part 2.1: Unleash Multi Phase (#8113)
• staking: Flexible generation of reward curve and associated tweaks (#8327)
• contracts: Expose rent parameter to contracts (#8231)
• pallet-staking: add RewardDestination::None for explictly not receiving rewards (#8168)
• Return babe configuration information in the babe api epoch functions (#8072)
• Assets: Remove zombies, introduce approvals (#8220)
• Self-sufficient account ref-counting (#8221)
• Init RuntimeLogger automatically for each runtime api call (#8128)

Client

• Storing multiple Justifications per block (#7640)
• Remove legacy network protocol (#8296)
• Rework telemetry to replace the use of tracing with an object we pass around (#8143)
• Decrease the peer reputation on invalid block requests (#8260)

API

• Migrate pallet-indices to pallet! (#8465)
• Migrate pallet-sudo to pallet! (#8448)
• Upgrade pallet atomic swap (#8452)
• Migrate pallet-utility to pallet attribute macro. (#8326)
• contracts: Reduce the API surface (#8359)
• Add tracing logic in pallet macro for hooks and dispatchables (#8305)
• Use the log crate to output contract generated messages. (#8403)
• Replace 'Module' with 'Pallet' in construct_runtime macro (#8372)
• Migrate pallet-babe to pallet attribute macro. (#8310)
• Migrate node authorization pallet to FRAME v2 (#8337)
• Migrate pallet-proxy to pallet attribute macro (#8365)
• im-online: use EstimateNextSessionRotation to get better estimates of session progress (#8242)
• Add on_idle hook (#8209)
• more clear randomness API for BABE (#8180)
• Custom RPC for Merkle Mountain Range pallet (#8137)
• pallet_macro: Generate default documentation for well known types (#8276)