Added more info to build menu descriptions

Changed descriptions in the build menu

Metal fences and Metal Fence Gates no longer create a player town
Fence Gates are now a little weaker than Makeshift Gates

Added a new gate to use with the fences
Slightly reduced the max height for placing fences
Darkened a part of the non-rusted texture and removed some leftover rust
Improved the UV mapping on the chain link fence and fixed a small hole