options: replace --wayland-disable-vsync with --wayland-internal-vsync

With the upcoming fixes to FIFO in wayland, it should be preferable to
use FIFO instead of our own hacky heuristic. This means
--wayland-disable-vsync should become a tristate option with an "auto"
behavior (not implemented in this commit). The semantics have to
slightly change so introduce --wayland-internal-vsync and deprecate
--wayland-disable-vsync.