Lua pinetree generation and sapling growing ABM. Cleanup file. Pointy top?

![screenshot_346806125](https://cloud.githubusercontent.com/assets/3686677/5296463/1a7042b2-7b9c-11e4-8e14-9bff9b176682.png)

I added a single central needles node as a pointy top, what do you think? Also, the trunk extends 3 nodes down into the ground as a simple root. Generation remains exactly the same otherwise but i have optimised the code so the code looks different. The volume around the sapling is scanned for snow nodes, deciding whether snow is placed on the needles.
MTgame team, let me know if the pointy top and root are okay.