Get rid of MSVC's __int64

Use either int64_t, uint64_t or long long and unsigned long long, defined as per C++11 standard

Minecraft.World/RiverLayer.h

@@ -5,6 +5,6 @@
 class RiverLayer : public Layer
 {
 public:
-	RiverLayer(__int64 seedMixup, shared_ptr<Layer>parent);
+	RiverLayer(int64_t seedMixup, shared_ptr<Layer>parent);
 	intArray getArea(int xo, int yo, int w, int h);
 };