More Sections + 2x render distance

More sections have been added:
+ Split w/ whirlpool
+ Lake w/ dense whirlpool cluster
+ Lake w/ sparse whirlpool cluster

Upon entry, a section's next sections now generate new sections,
increasing the render distance by 2x (in other words +400 units). A
problem with this is the section generation causes a noticable lag.
Unsure how to combat this, perhaps vsync or a lower framerate will do.
If all else fails, simply remove some of the bushes/trees and lower the
polycount with lower poly bushes/trees.