Added buildable scaffolding building

I added Scaffolding to improve building.

Based on https://github.com/vbawol/DayZ-Epoch/commit/9562c319c16a2c54655708f3d27a3298aefb73d3

Im currently unable to test it, ill test it when i am @ home about 20:00 GMT+1, or someone else who can test it.

http://util.fankservercdn.com/arma2/object-library/images/Land_Misc_Scaffolding.jpg