Implement terrain file reading to generate navmeshes in the future (#703)

* Implement terrain file reading to generate navmeshes in the future

* Make Emo's suggested changes.

dNavigation/dTerrain/RawMesh.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <vector>
+
+#include "NiPoint3.h"
+
+struct RawMesh {
+	std::vector<NiPoint3> m_Vertices;
+	std::vector<uint32_t> m_Triangles;
+};