Revert "Project modernization (#630)"

This code was not tested and breaks in Release builds, reverting to restore
functionality of the nightly. All in-game menus do not work and generating
a world crashes.

This reverts commit a9be52c41a.

Minecraft.World/StructureStart.cpp

@@ -9,14 +9,14 @@
 StructureStart::StructureStart()
 {
 	chunkX = chunkZ = 0;
-	boundingBox = nullptr;		// 4J added initialiser
+	boundingBox = NULL;		// 4J added initialiser
 }
 
 StructureStart::StructureStart(int x, int z)
 {
 	this->chunkX = x;
 	this->chunkZ = z;
-	boundingBox = nullptr;
+	boundingBox = NULL;
 }
 
 StructureStart::~StructureStart()