Welding tool sprite updates

"Oh boy another stupid simple sprite replacement by paprika"

YOU THOUGHT WRONG

![ass](https://cloud.githubusercontent.com/assets/7247232/4536018/9d120658-4dbe-11e4-9139-2c5cb6d4434a.png)
![ff](https://cloud.githubusercontent.com/assets/7247232/4536019/9dcb8dee-4dbe-11e4-96fe-e35b1df6c77f.gif)

DYNAMIC WELDING TOOL FUEL LEVEL FEEDBACK

AND EMPTY FUEL BLINKING

!!!