Since commit 7253c5ca (Bug 682071-cogl/cogl-sdl.h: MSVC: Link to SDL when
apps are built), on Visual C++ we link to SDL.lib and SDLmain.lib using
a #pragma comment directive in cogl/cogl-sdl.h, so we no longer need
specific project configs for Cogl programs which build against a Cogl built
with SDL. This removes those unneeded configs.
Also "install" cogl/cogl-sdl.h when Cogl is built with the SDL winsys, as
it is a needed header
cfdc1c95eb