(WIP) In-game settings

![minetests1](https://f.cloud.github.com/assets/1996449/265683/8568182e-8db9-11e2-9309-5d04d0953231.png)
![minetests2](https://f.cloud.github.com/assets/1996449/265690/85d807b0-8db9-11e2-9d5d-46d1f01528eb.png)
![minetests3](https://f.cloud.github.com/assets/1996449/265688/85996cb2-8db9-11e2-814e-fb2b09663e89.png)
![minetests4b](https://f.cloud.github.com/assets/1996449/267580/79c4f8dc-8ea1-11e2-9829-bcebe120b40d.png)
![minetests5](https://f.cloud.github.com/assets/1996449/265687/859b18be-8db9-11e2-8d72-bc780ca36d92.png)
![minetests6](https://f.cloud.github.com/assets/1996449/265686/8598bede-8db9-11e2-8812-cd70cd980c32.png)
![minetests7](https://f.cloud.github.com/assets/1996449/265684/85791386-8db9-11e2-8d54-a2437e4596b1.png)
![minetests8](https://f.cloud.github.com/assets/1996449/265685/858b9ce0-8db9-11e2-85e5-844387ebc14e.png)