- Like perform operations, cancel_operations can add/remove an account from negative accounts system.
- Balances checks are now performed against real_balance instead of balance. So if someone with a balance_offset go, for real, to positive land (ie even without taking into account the balance offset), its account is removed from the negative system.
- Fix bug on real_balance when negative exists but balance_offset is not set.
Fixes #156 (closed).