Refactor libseat code for Xlibre and add to meson.build:
* update meson for seat-libseat
* refactor code:
* seatd-libseat.c - add aditional private include headers
* add cast to libseat_set_log_handler argument 1 for (libseat_log_func),
for warning silencing
* make seatd_libseat_init to accept keeptty state as parameter
* include xf86Events, xf86_priv - make visible xf86VTLeave for seatd code (it
is neccesary because seatd can force console leave)
Signed-off-By: Tautvis <gtautvis@gmail.com>
8d90cd0060