Added TwoHeights shape generator.

This is a faster shape generator that can generate overhangs and has biome awareness.

src/Generating/ShapeGen.cpp

@@ -9,6 +9,7 @@
 #include "DistortedHeightmap.h"
 #include "EndGen.h"
 #include "Noise3DGenerator.h"
+#include "TwoHeights.h"
 
 
 
@@ -121,6 +122,10 @@ cTerrainShapeGenPtr cTerrainShapeGen::CreateShapeGen(cIniFile & a_IniFile, cBiom
 	{
 		res = std::make_shared<cNoise3DComposable>(a_Seed);
 	}
+	else if (NoCaseCompare(shapeGenName, "TwoHeights") == 0)
+	{
+		res = CreateShapeGenTwoHeights(a_Seed, a_BiomeGen);
+	}
 	else
 	{
 		// No match found, force-set the default and retry