* Spliting gasometer out of interpreter
* Choosing right gas calculations implementation based on supplied gas
* Moving verification out of gasometer
* MemGasCost benchmark.
Conflicts:
ethcore/src/evm/benches/mod.rs
* Some simple benchmarks
* Benchmark for simple loop
* Calculating gas_for_memory only when it's actually needed
* Removing superfluous newline [ci skip]
* refactor externalities::ret to take self by-value, add GasLeft enum, and alter evm::Result.
* remove unused imports, StopExecutionWithGasLeft variant
* adjust tests
* remove extraneous call to reserve
* update json_tests Ext to match new trait
* adjust executive json_test
* have evms own their memory for their entire lifetime
* make finalize API more friendly
* indentation fix
[ci skip]
