only creating a new Plane() and setting the water
height uniform when the water height changes.
Also got rid of the redundant dot() product and
Vector3f allocation in the process.
One can now mark a texture param in a material definition as linear by using -Linear at the end of the parameter declaration (case insensitive).
An Image bound to a material texture param in a linear color space will have its ColorSpace set to linear when bound to the material by mat.setTexture("name", texture);
Added the -LINEAR flag to all texture param that needed it in stock materials (lighting.j3md, terrainLighting.j3md, different Filter materials).
