This implements EIP161. Several notes:
- AccountPatch::initial_create_nonce handles EIP161(a).
- AccountPatch::empty_considered_exists handles EIP161(b)(c)(d).
- AccountPatch::allow_partial_change specify whether AccountChange::IncreaseBalance can happen. However, if in the case of EIP161 being enabled, allowing this would mean that the client needs to check for zero balance accounts in the end touched by IncreaseBalance to comply EIP161(d).
- AccountPatch::allow_partial_change also has impact on parallel execution. When it is disabled, parallel execution would be slow due to the dependency on beneficiary address. If a client decides to take advantage of SputnikVM's parallel execution, it is recommended to always enable this and deal with EIP161(d).
- premark_exists is removed as it is not needed any more.