Adv inv "How much" input only digits, show oveload, and diversity in the path of zombies

1) Show oveload on UI time of move.
2) Adv inv "How much" input only digits
3) Diversity in the promotion of zombies to the player
![image1](https://f.cloud.github.com/assets/4676406/1663095/a480913e-5c0b-11e3-82b8-fb74c13fd275.png)