Viewport, Platforms: SDL: Fixed initial focus click being ignored as a mouse button. GLFW: Fixed mouse cursor support for multi-viewport with GLFW 3.3 (current master) - somehow doesn't appear to work with GLFW 3.2 but I'm not too fussed about it. (#1542)
// We already retrieve global mouse position, SDL_CaptureMouse() also let the OS know our drag outside boundaries shouldn't trigger, e.g.: OS window resize cursor
// We already retrieve global mouse position, SDL_CaptureMouse() also let the OS know e.g. that our imgui drag outside the SDL window boundaries shouldn't trigger the OS window resize cursor
// The function is only supported from SDL 2.0.4 (released Jan 2016)
// SDL2 by default doesn't pass mouse clicks to the application when the click focused a window. This is getting in the way of our interactions and we disable that behavior.