Wasm runtime update

[NikVolf]

• call now obliged to specify gas limit
• overall update of wasm-tests and corresponding gas costs
• some environment for calls was fixed to be passed correctly

[pepyakin]

Is it really a correct signature? In pwasm-std/pwasm-ethereum it is defined like

		pub fn ccall(
			gas: i64,
			address: *const u8,
			val_ptr: *const u8,
			input_ptr: *const u8,
			input_len: u32,
			result_ptr: *mut u8,
			result_len: u32,
		) → i32;

which have 7 arguments, but in code above it have only 6.

[NikVolf]

Nice catch, regular call lacks dedicated test also

[pepyakin]

Also, could you please update method signature comments, e.g.

https://github.com/paritytech/parity/blob/d5b81ead71a8c4b3eca5cc3dd18e575534cf73a6/ethcore/wasm/src/runtime.rs#L305-L314