Rebootless graphics switching

This changes out how the current graphics switching works, enabling
asusd to stop/start the display-manager to enable/disable PCI devices
and add/remove drivers as required.

All existing graphics modes and commands still work as normal.

G-Sync enable is now only through the bios setting, and on reboot
will set all relevant settings to Nvidia mode.

daemon/src/lib.rs

@@ -1,6 +1,7 @@
 #![deny(unused_must_use)]
 /// Configuration loading, saving
 pub mod config;
+pub(crate) mod config_old;
 /// Control of AniMe matrix display
 pub mod ctrl_anime;
 /// Control of battery charge level