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/RenderTarget.cpp

@@ -25,5 +25,5 @@ bool NzRenderTarget::SetActive(bool active)
 
 void NzRenderTarget::Desactivate()
 {
-	// Seuls les target sans contextes (ex: RenderTexture) nécessitent une désactivation
+	// Seuls les target sans contextes (ex: NzRenderTexture) nécessitent une désactivation
 }