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/Utility/PixelFormat.hpp

@@ -35,6 +35,16 @@ enum nzPixelFormat
 	nzPixelFormat_RGB5A1,  // 1*nzUInt16
 	nzPixelFormat_RGB8,    // 3*nzUInt8
 	nzPixelFormat_RGBA8,   // 4*nzUInt8
+	/*
+	nzPixelFormat_Depth16,
+	nzPixelFormat_Depth24,
+	nzPixelFormat_Depth24Stencil8,
+	nzPixelFormat_Depth32,
+	nzPixelFormat_Stencil1,
+	nzPixelFormat_Stencil4,
+	nzPixelFormat_Stencil8,
+	nzPixelFormat_Stencil16,
+	*/
 
 	nzPixelFormat_Count
 };