Clean Up Attempted Roll back fix

This commit mainly cleans up the unnecessary code . As well as fixing the POW subsidy and applying the Compute max bits fix from Balthazar / CryptoManiac. It is unclear to me as to if this will cure the chain roll back issues as it is a rather unique situation. But these changes needed to be done either way. Lots of code was removed and reworked correctly. Hopefully this fixes the rollback