This will help us deal with shader name collision. Breaks the Windows
build for the moment, unfortunately.

Not all programs support this feature for now, but that’s because they
don’t support the scene framework either, and will need patching. Also
the default postprocess is deliberately exaggerated for now.

Merge threadbase.h into thread.h since we no longer need to have “secret”
thread implementations; all the platforms we care about have std::thread
or just don’t support threads at all.

SDL2: Mouse is back ! With correct focus support
SDL2: Added typing support with keyboard
ShaderBuilder: Refactored and simplified Shader block creation
Several warning removal
Fixed Image::Copy

Added Texture (by image) update in TextureImage (and tileset)
Added lolimgui first integration pass

Added InputProfile in Controller
Added ExecLuaCode

Big FAT pass on windows-warning. It is better now.

support for enable_if and other template metaprogramming techniques),
for Clang (related to static const template class member initialisation)
and for GCC (related to forward declaration of non-int enum classes).

for the next implementation of large float numbers.

can reuse it for other noise implementations.

wanted convolution or dithering kernels.