First part of render texture commit

Added NzContext::EnsureContext and NzContext::GetThreadContext
Added NzCube
Added NzRect::GetCenter
Added methods to send vectors to shaders
Added NzRenderer::SetViewport
Fixed NzRect::ExtendTo calculations
Fixed NzImage::Update checks with level > 0
No longer use glTexStorage when creating a texture to prevent a bug
NzBuffer's Lock and Unlock operations renamed to Map and Unmap
NzVector2/3/4 can now cast implicitly to a pointer
Optimized compilation time of String.hpp
Optimized normalisaton of quaternions
Optimized passing uniforms to shaders
Quaternion now automaticaly Normalize h
Removed macro definition of NAZARA_RENDERER_OPENGL from Renderer
Removed implicit cast from NzVector2/3/4 to NzString
Renamed nzBufferLock to nzBufferAccess
Renamed NzRenderTarget::CanActivate to IsValid

include/Nazara/Math/Cube.hpp

@@ -0,0 +1,58 @@
+// Copyright (C) 2012 Jérôme Leclercq
+// This file is part of the "Nazara Engine".
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#pragma once
+
+#ifndef NAZARA_CUBE_HPP
+#define NAZARA_CUBE_HPP
+
+#include <Nazara/Core/String.hpp>
+#include <Nazara/Math/Vector3.hpp>
+
+template<typename T>
+class NzCube
+{
+	public:
+		NzCube();
+		NzCube(T X, T Y, T Z, T Width, T Height, T Depth);
+		NzCube(T cube[6]);
+		template<typename U> explicit NzCube(const NzCube<U>& rect);
+		NzCube(const NzCube& rect) = default;
+		~NzCube() = default;
+
+		bool Contains(T X, T Y, T Z) const;
+		bool Contains(const NzVector3<T>& point) const;
+		bool Contains(const NzCube& rect) const;
+
+		void ExtendTo(const NzVector3<T>& point);
+		void ExtendTo(const NzCube& rect);
+
+		NzVector3<T> GetCenter() const;
+
+		bool Intersect(const NzCube& rect) const;
+		bool Intersect(const NzCube& rect, NzCube& intersection) const;
+
+		bool IsValid() const;
+
+		NzString ToString() const;
+
+		operator NzString() const;
+
+		T& operator[](unsigned int i);
+		T operator[](unsigned int i) const;
+
+		T x, y, z, width, height, depth;
+};
+
+template<typename T>
+std::ostream& operator<<(std::ostream& out, const NzCube<T>& vec);
+
+typedef NzCube<double> NzCubed;
+typedef NzCube<float> NzCubef;
+typedef NzCube<int> NzCubei;
+typedef NzCube<unsigned int> NzCubeui;
+
+#include <Nazara/Math/Cube.inl>
+
+#endif // NAZARA_CUBE_HPP