add new terrain, renderer as simple point cloud #41

reuse the old terrain generator =)
add vertex height texture #41
pass the terrain actor to pxScene #41
draw terrain quads as triangle strips #41
split terrain implementation into terrain/tile #41
Merge remote-tracking branch 'origin/nirvana_40' into nirvana_terrain_40
different rendering for base and water tile #41
enable water alpha blending #41
draw terrain with triangle strip #41
Merge remote-tracking branch 'origin/nirvana_40' into nirvana_terrain_40

Conflicts:
	CMakeLists.txt
add terrain type texture to base tile #41
create heightfield in own objects, not pxHeightFieldSamples #41
use samplerBuffers/Textures for heightfield and terraintypes #41

using physx heightfield grid definitions: row=x, column=z, in row major order,
use elements/materials for shading #41
fix max (do not define macro in windows includes) #41

find a better way to do this..
Merge remote-tracking branch 'origin/nirvana_40' into nirvana_terrain_40

Conflicts:
	CMakeLists.txt
	src/world.cpp
	src/world.h
more elegant way to suppress min/max macro definition in windows headers #41
use front left vertex in terrain quads for terrain information #41

reuse geometry shader from old osg terrain implementation
apply changes to water shaders #41
calculate terrain normals #41