v. 2.7 Happy Holydays

Happy Holidays to all, to celebrate I have some gifts for You:

1. New Arcade Mode for single player fun;
2.  IA bot has got now different behaviours following differents strategies;
3.  Added 3 new cars (old Fiat Panda styled);
4. New Cameras, now you can swap with the "C" key;
5. Slow Motion mode, now it is possible activate/disactivate this mode with the "left shift" key;
6. Little countdown at the start;
7. Improved code now permit better perfomances;
8. Some bugs fixed.