checkpoints.cpp depends on main, it can use mapBlockIndex directly
Introduce BlockMap type for mapBlockIndex
Use boost::unordered_map for mapBlockIndex
Use memcmp for uint256 equality/inequality
Merge pull request #4838

1e4f87f Use memcmp for uint256 equality/inequality (Pieter Wuille)
8a41e1e Use boost::unordered_map for mapBlockIndex (Pieter Wuille)
145d5be Introduce BlockMap type for mapBlockIndex (Pieter Wuille)
a0dbe43 checkpoints.cpp depends on main, it can use mapBlockIndex directly (Pieter Wuille)