Get rid of the static chainMostWork (optimization)
Allow ActivateBestChain to release its lock on cs_main
Move all post-chaintip-change notifications to ActivateBestChain
Push cs_mains down in ProcessBlock
Merge pull request #4148

18e7216 Push cs_mains down in ProcessBlock (Pieter Wuille)
202e019 Move all post-chaintip-change notifications to ActivateBestChain (Pieter Wuille)
4e0eed8 Allow ActivateBestChain to release its lock on cs_main (Pieter Wuille)
77339e5 Get rid of the static chainMostWork (optimization) (Pieter Wuille)