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.

of slightly overkill Image objects.