V2.5.6 stable (#10961)

-  Fix cargo audit (#10921)
  - Add support for Energy Web Foundation's new chains (#10957)
  - Kaspersky AV whitelisting (#10919)
  - Avast whitelist script (#10900)
  - Docker images renaming (#10863)
  - Remove excessive warning (#10831)
  - Allow --nat extip:your.host.here.org (#10830)
  - When updating the client or when called from RPC, sleep should mean sleep (#10814)
  - added new ropsten-bootnode and removed old one (#10794)
  - ethkey no longer uses byteorder (#10786)
  - Do not drop the peer with None difficulty (#10772)
  - docs: Update Readme with TOC, Contributor Guideline. Update Cargo package descriptions (#10652)

ethcore/res/ethereum/ropsten.json

@@ -2654,7 +2654,7 @@
 		]
 	},
 	"nodes": [
-		"enode://6332792c4a00e3e4ee0926ed89e0d27ef985424d97b6a45bf0f23e51f0dcb5e66b875777506458aea7af6f9e4ffb69f43f3778ee73c81ed9d34c51c4b16b0b0f@52.232.243.152:30303",
+		"enode://d6cb8cba18828397e22e8852324af7e970b57cadbbd94aba6124790d1895728311b1f274e45d44a7a22b4276726903130a11ac2de19af5bc9294998f948eaad4@144.217.72.209:30303",
 		"enode://94c15d1b9e2fe7ce56e458b9a3b672ef11894ddedd0c6f247e0f1d3487f52b66208fb4aeb8179fce6e3a749ea93ed147c37976d67af557508d199d9594c35f09@192.81.208.223:30303",
 		"enode://30b7ab30a01c124a6cceca36863ece12c4f5fa68e3ba9b0b51407ccc002eeed3b3102d20a88f1c1d3c3154e2449317b8ef95090e77b312d5cc39354f86d5d606@52.176.7.10:30303",
 		"enode://865a63255b3bb68023b6bffd5095118fcc13e79dcf014fe4e47e065c350c7cc72af2e53eff895f11ba1bbb6a2b33271c1116ee870f266618eadfc2e78aa7349c@52.176.100.77:30303",