Changes to the Clowncart

- Commented fuel method removed
- Formatting, use span. Stop src. typecasting
- Maximum health is now 1000 (cannot be boosted over this)
- User is now warned if adding more fuel than needed, and the proc returns
- User is now warned if improving/repairing won't work
- Banana peels now only remove one second of emp stun, banana seeds now remove it entirely
- Added some visible_message to some actions
- Clarify some messages
- When driving while the clowncart runs out of fuel, it will now forcefully eject you (weaken for 5 seconds)
- EOL

Should address #2146