added trapper, and with it some reworks to the code to make it a bit cleaner! - stats for bullets are stored in lists instead, stats that change such as bullet health which decreases on impact and bullet speed which slows down on traps are given their own private variable to change. - bullets now have health and utilize their penetration stat to speed up the collision. - enemies receive damage based on the tank you have, their health is also rebalanced to match the bullets. - some other rearrangements to the code
