* Merge with Debian. Remaining changes:
  - debian/control.in:
    + Build-depend on libsystemd-login-dev & libsystemd-daemon-dev
    + Depend on gdm instead of gdm3
  - debian/patches/40_change-pam-name-to-match-gdm.patch:
  - debian/patches/revert-suspend-break.patch:
    + Disabled, not needed on Ubuntu
  - debian/patches/ubuntu-lightdm-user-switching.patch:
    + Allow user switching when using LightDM.
  - debian/patches/ubuntu_lock_on_suspend.patch
    + Respect Ubuntu's lock-on-suspend setting.
      Disabled until it can be rewritten.
  - debian/patches/git_relock_screen_after_crash.patch:
    + Backport fix to ensure session is locked after crash
* debian/patches/revert-input-source-changes.patch:
  - Temporarily revert input source changes that need gnome-settings-daemon
    and gnome-control-center 3.8.3 to be useful
* debian/patches/revert-notification-settings-link.patch:
  - Don't link to Notification Settings since that's only available
    with gnome-control-center >= 3.8.