Changes to the Account class

Changed Account::sumTransaction(), Account::refreshBalance() use
TransactionType::opCode when summing or calculating balances.
Changes to Customer class

Changed Customer::getStatement() and Customer::getStatementForAccount()
to use new TransactionType(s) to determine balances
Changes To Transaction class(s)

- Removed all Transaction::commit() implementations as we are not going
to implement.
Changes to Utils class

Added new interest rate calculations
Sync test harness to code

- Test interest rate calculations
- Removed superfluous tests
-
Re-sync of documentation

- Regenerate all javadocs
- Added comments in REFACTOR.NOTES
missed javadoc updates