Parity Ethereum 2.0.4-beta

Parity-Ethereum 2.0.4-beta is a bug-fix release to improve performance and stability:

• eth_coinbase now provides an actual account for light clients
• don't report skipped primaries when empty steps are enabled in proof-of-authority networks
• fix snapshot restoration failure on windows
• check warp sync status for eth_getWorks

System	Architecture	Binary	SHA256 Checksum
	x64	parity.exe	b0c172a19ea199a9ab20b25a4d7e93d90835ee5731679d7a320615c9e72efac8
	x64	parity	768b397076db7e51fd62cefc632723272162bae872a65bba7a6f5cbc523fa6c3
	x64	parity	58a626c4984444d0d80e8a700b90fecc9d81c49e38a5521bf05ac79e9dd7f010
	x86	parity	0942c5403ad1837cb00cb0e03377560511a806d7c420f5a94f5d0ef1e699826b
	armv7	parity	984b5a1a0bc8512bbb3c2d307d80bc079c2de8ab996b9c56fe9a88d0e9059f10
	arm64	parity	62eaf55bfc01249bfe2db244b92a82f5e4d19bdeb528353ac4825cda7eb7937b
System	Option	-	Resource
	Homebrew	-	github.com/paritytech/homebrew-paritytech
	Snapcraft	-	snapcraft.io/parity
	Docker	-	hub.docker.com/r/parity/parity
	All binaries	-	vanity-service.parity.io/parity-binaries?version=v2.0.4

The full list of included changes:

• Beta backports to 2.0.4 (#9452)
  • Parity-version: bump beta to 2.0.4
  • [Light/jsonrpc] Provide the actual account for eth_coinbase RPC and unify error handeling for light and full client (#9383)
    • Provide the actual account for eth_coinbase
    • The previous implementation always provided the zero address on eth_coinbase RPC. Now, instead the actual address is returned on success or an error when no account(s) is found!
    • Full client eth_coinbase return err
    • In the full-client return an error when no account is found instead of returning the zero address
    • Remove needless blocks on single import
    • Remove needless static lifetime on const
    • Fix rpc_eth_author test
  • Parity: print correct keys path on startup (#9501)
  • Aura: don't report skipped primaries when empty steps are enabled (#9435)
  • Only check warp syncing for eth_getWorks (#9484)
    • Only check warp syncing for eth_getWorks
    • Use SyncStatus::is_snapshot_syncing
  • Fix Snapshot restoration failure on Windows (#9491)
    • Close Blooms DB files before DB restoration
    • Address Grumbles