The order and way include macros were structured was chaotic, with no
real common thread between files. Try to tidy up the mess with some
common scheme, to make things look less messy.
This goes through modifying XI2 device properties, either common ones (eg.
set on every device) or those specific to the libinput X11 driver. Keyboard
repeat/rate are set through core and XKB APIs.
https://bugzilla.gnome.org/show_bug.cgi?id=739397
