This splits the WaterManager class, used for water rendering, in a graphics/ component that holds the water settings and related data, and a renderer/ component that holds textures and stuff like that.
The WaterManager is now held by the GameView, since that seems to make sense.
The renderer itself is mostly holding stuff used by the terrain renderer, and there's some more refactoring opportunities in there for sure.
The goal is to make the rendering-bits (i.e. OpenGL) more independent from graphics stuff, and thus easier to change.