State Network Updates

[ScottyPoi]

First round of updates to state network:

• Removes old distance formula

  • TODO: Define distance to be same as History Network

• Removes Commentary on "cold node" problem

• Replaces account_trie_proof data type

• Adds account_trie_node data type

• Replaces contract_storage_trie_proof data type

• Adds* contract_trie_node data type

• Modifies contract_bytecode data type

• Defines new functions:

  • combine_path_and_nodehash
  • rotate

• Defines nibble types

  • nibble
  • NibblePair
  • Nibbles

Also includes new TODOs for completing spec design