[Enhancement] Use user_id for pool checking instead of IPs

[HVRVKVT]

Using PIDs instead of ip_checking to prevent voting more than once, is not only preferable, but also a more robust solution. While one could easily change IP, who would want to reset their PID just to vote once more?

[HDVinnie]

This needs to be removed all together. Instead just check user_id. The poll system needs to be refactored. It is old and was built like this because early UNIT3D supported both usage for a private or public tracker.

[HVRVKVT]

even better 👍