- Add config option `no_logind`: Don't use logind to see if all sessions are
  logged out and therefore safe to change mode. This will be useful for people not
  using a login manager, however it is not guaranteed to work unless all graphical
  sessions are ended and nothing is hooking the drivers. Ignored if `always_reboot`
  is set.
- Add config option `logout_timeout_s`: The timeout in seconds to wait for all user
  graphical sessions to end. Default is 3 minutes, 0 = infinite. Ignored if
  `no_logind` or `always_reboot` is set.
- Add new dbus method: `PendingMode`, to check if a mode change is required
- Add new dbus method: `PendingUserAction`, to check if the user is required to perform an action
- Add new dbus method: `Config`, to get the current base config
- Add new dbus method: `SetConfig`, to set the base config
- Add `-p, --pend-action` CLI arg to get the pending user action if any
- Add `-P, --pend-mode` CLI arg to get the pending mode change if any`
- Add ability to read `supergfxd.mode=` from kernel cmdline on startup and set the mode appropriately
- CLI option `--force` was unused, it is now removed.