* ECIP 1041 - Remove Difficulty Bomb (#7905)
Enable difficulty bomb defusion at block:
- 5900000 on Ethereum Classic mainnet,
- 2300000 on morden testnet.
Reference:
https://github.com/ethereumproject/ECIPs/blob/master/ECIPs/ECIP-1041.md
* spec: Validate required divisor fields are not 0 (#7933)
* Add validate_non_zero function
It's used to validate that a Spec's uint field used as a divisor is not zero.
* Add deserialize_with to gas_limit_bound_divisor
Prevents panics due to divide-by-zero on the gas_limit_bound_divisor
field.
* Add deserialize_with to difficulty_bound_divisor
Prevents panics due to divide-by-zero on the difficulty_bound_divisor
field.
* Add validate_optional_non_zero function
Used to validate Option<Uint> divisor fields.
* Use deserialize_with on optional divisor fields.
* Add #[serde(default)] attribute to divisor fields
When using `#[serde(deserialize_with)]`, `#[serde(default)]` must be specified so that missing
fields can be deserialized with the deserializer for `None`.
* Kovan WASM fork code (#7849)
* kovan fork code
* introduce ethcore level vm_factory and let it fail
* fix json tests
* wasmcosts as option
* review changes
* wasm costs in parser
* fix evm tests
* review fixes
* fix test
* remove redundant json field
* update back-references more aggressively after answering from cache (#7578)
* Add new EF ropstens nodes. (#7824)
* Add new EF ropstens nodes.
* Fix tests
* Add a timeout for light client sync requests (#7848)
* Add a timeout for light client sync requests
* Adjusting timeout to number of headers
* Flush keyfiles. Resolves#7632 (#7868)
* Fix wallet import (#7873)
* rpc: generate new account id for imported wallets
* ethstore: handle duplicate wallet filenames
* ethstore: simplify deduplication of wallet file names
* ethstore: do not dedup wallet filenames on update
* ethstore: fix minor grumbles
* [WASM] mem_cmp added to the Wasm runtime (#7539)
* mem_cmp added to the Wasm runtime
* schedule.wasm.mem_copy to schedule.wasm.mem_cmp for mem_cmp
* [Wasm] memcmp fix and test added (#7590)
* [Wasm] memcmp fix and test added
* [Wasm] use reqrep_test! macro for memcmp test
* wasmi interpreter (#7796)
* adjust storage update evm-style (#7812)
* disable internal memory (#7842)
