Update HDW todo list.
Wallet: add convenience methods to vend Address objects for currentKey/freshKey
Wrap coin-ish BigIntegers into Coin class.
Refactor internal coin representation from BigInteger to long.
Move coin related methods and constants from Utils into Coin.
Clean up Coin API for multiplications and divisions.
Remove weird constructors.
Remove weird value accessors.
Rename Coin.toNanoCoin(String) to Coin.parseCoin(String).
Rename Coin.toNanoCoins(coins, cents) to Coin.valueOf(coins, cents).
Clean up coin constants and make more use of it.
Add missing @Override annotations.
Clear a lot of compiler warnings because of unparameterized types.
Remove unused imports.
Fix website link in README
Deprecate Coin.longValue() in favour of accessing Coin.value directly.
Replace or remove remaining misuses of the term 'nanocoin'.
Access NetworkParameters.MAX_MONEY in a static way.
Fix 'java.math.Coin' in the JavaDocs.
Rename Coin.NANOCOIN to Coin.MICROCOIN.