Spout for ARM processors

Thanks to the work of Hernan Martinez, Spout can now be built uisng computers with an Arm processor, for Windows on ARM for DirectX 11, DirectX 12 and OpenGL. Arm built applications can also share textures with x86 (Intel/AMD) applications running under emulation.

Selecting a simple “Arm build” checkbox in CMake is all that is required. Changes are minor and all files are available in the Beta branch.

The first application for this is Stellarium, based on OpenGL and using SpoutLibrary. Currently available as a weekly snapshot, a future release will be available from the Stellarium Github repository.