Xlib has really terrible headers that declare non-namespaced
macros and typedefs for common words.
Just wasted 10 minutes trying to figure out why a unit test failed
to build before I remembered it was Xrandr.h conflicting with our
enum class members again.
To fix the issue, this removes the Display* parameter from the
EnableScreensaver function (which was unused) so we don't have
to include Xrandr.h anymore.
The "X.h" header *just* contains protocol constants, not functions or
typedefs - so stuff like "Display" and "Window" are not defined unless
you include "Xlib.h".
"Xrandr.h" happens to include "Xlib.h" itself, so enabling xrandr
effectively worked around this issue.
