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

src/Nazara/Renderer/HardwareBuffer.hpp

@@ -28,8 +28,8 @@ class NzHardwareBuffer : public NzBufferImpl
 
 		bool IsHardware() const;
 
-		void* Lock(nzBufferLock lock, unsigned int offset = 0, unsigned int length = 0);
-		bool Unlock();
+		void* Map(nzBufferAccess access, unsigned int offset = 0, unsigned int length = 0);
+		bool Unmap();
 
 	private:
 		GLuint m_buffer;