ERC-1077 Gas relay for contract calls

StagnantERCcreated 2018-05-041 later proposal build on itrequires ERC-20, ERC-191, ERC-1271, EIP-1344

Authors: Alex Van de Sande, Ricardo Guilherme Schmidt (@3esmit)

Functions this standard introduces (4)

`0xee60cd10`	`executeGasRelay(bytes,uint256,uint256,address,address,bytes)`
`0xb350c537`	`executeGasRelayERC191Msg(uint256,bytes,uint256,uint256,address,address)`	view
`0xcb914962`	`executeGasRelayMsg(uint256,bytes,uint256,uint256,address,address)`	pure
`0x52631ab4`	`lastNonce()`

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Later proposals that name this one in their requires field.