ERC-2917 Staking Reward Calculation

StagnantERCcreated 2020-08-28

Authors: Tony Carson, Mehmet Sabir Kiraz, Süleyman Kardaş

ERC-165 interface ids

Computed here as the XOR of the selectors each interface defines.

IERC2917 0x99c1dec4

`0x7b381b35`	`changeInterestRatePerBlock(uint256)`
`0x4afa66d6`	`decreaseProductivity(address,uint256)`
`0x28e964e9`	`getProductivity(address)`	view
`0x36f04e45`	`increaseProductivity(address,uint256)`
`0xbfc8b208`	`interestsPerBlock()`	view
`0x1249c58b`	`mint()`
`0x159090bd`	`take()`	view
`0x0e0b6eb5`	`takeWithBlock()`	view

`0xdd62ed3e`	`allowance(address,address)`	ERC-20
`0x095ea7b3`	`approve(address,uint256)`	ERC-20
`0x70a08231`	`balanceOf(address)`	ERC-20
`0x313ce567`	`decimals()`	ERC-20
`0x06fdde03`	`name()`	ERC-20
`0x95d89b41`	`symbol()`	ERC-20
`0x18160ddd`	`totalSupply()`	ERC-20
`0xa9059cbb`	`transfer(address,uint256)`	ERC-20
`0x23b872dd`	`transferFrom(address,address,uint256)`	ERC-20

Topic0 is the keccak256 hash of the signature, which is what a log filter matches on.

`0xc44c80d7c6ac73ee13b2c62e50522dadb6c646b4509ca93e52a45abb38a78e33`	`InterestRatePerBlockChanged(uint256,uint256)`
`0x6c0a24b06ee7f1d9c3c6680c7328531c32bc59cd665436fc686f973cb8c01be7`	`ProductivityIncreased(address,uint256)`
`0xddb757202feefdd10c1666f1bb8f9744309ab811b6ef3ec0404a20c36e426697`	`ProductivityDecreased(address,uint256)`