This preparation is needed for subsequent
EIPs included in London.
- Add London to Fork enum
- Block number to fork
- Parsing London fork in chain config
- Prepare gas costs table for London
- Prepare EVM opcode dispatcher for London
- Block rewards for London
- Prepare hive script for London
hive always set 'HIVE_FORK_DAO_VOTE' to '1'.
set 'daoForkSupport' to 'true' if only 'HIVE_FORK_DAO_BLOCK'
is set by hive, not depends only on 'HIVE_FORK_DAO_VOTE'.
This is because 'nimbus-eth1' internal is different compared to 'geth'.
this changes is required due to recent #654.
custom genesis and chain config parser are fixed
and the genesis fields are grouped into "genesis"
field, similar with chain config fields,
they are grouped in "config" field.