Removal of USD Rewards from Mining Contract

https://gov.dollarprotocol.com/t/suspension-removal-of-usd-rewards-from-mining/15

TL:DR add a USD Deletion whitelist that checks an address. The Whitelist is controlled by the owner and will be reserved for only the mining contracts and their respective pools. When any user interacts with those contracts, the USD will be deleted out of existence, thereby allowing just SHARE to be distributed.