Proof of liquidity Rewards rework

[AntonAndell]

Rewards on Balanced will not also accept external reward tokens. Initially it will be sICX from emissions. The update did not seem to introduce any breaking changes that i could find from testnet UI but should be double checked. Get Baln holding will be replaced with getRewards, which will return a map of token Address => amount @External(readonly = true) BigInteger getBalnHolding(String _holder);

@External(readonly = true) Map<String, BigInteger> getRewards(String _holder);

Removed method that could be checked for BigInteger getAPY(String _name); Map<String, BigInteger> recipientAt(BigInteger _day); List<String> getRecipients(); Map<String, Object> distStatus(); Map<String, BigInteger> getRecipientsSplit();

New APY calculations: to be discussed when we get to it