[lightdm-ubuntu] Huge list of changes:

Update to version 1.5.1 with Ubuntu release 0ubuntu1

- File: 0001_pam_systemd.patch
  + Refreshed
- File: PKGBUILD
  + Don't depend on GTK or Qt(4,5). LightDM isn't toolkit-dependent,
    the greeters are
  + Update dependencies, build dependencies, and optional dependencies
  + Remove old configuration files from the backup array
  + Add PAM configuration for lightdm-greeter
  + Add PolicyKit rules from Fedora
  + Add patches from Fedora
  + Remove initscripts startup script
- File: guest-session-add-default-gsettings-support.patch
  + Refreshed
- File: guest-session-cross-distro.patch
  + Refreshed
- File: lightdm
  + Removed
- File: lightdm-1.5.1-systemd_login1_power.patch
  + Patch from Fedora which allows LightDM to use systemd's login1
    DBus interface instead of the ConsoleKit interface
- File: lightdm-autologin.pam
  + Merge from AUR package lightdm-devel
- File: lightdm-greeter.pam
  + Same as lightdm-autologin.pam
  + Commented out the password module. The greeter shouldn't care about
    password changing
- File: lightdm-lock-screen-before-switch.patch
  + Patch from Fedora to try to lock the session before switching to
    another user
- File: lightdm-plymouth.service
        lightdm.service
  + Merge changes from Fedora
    - Set Documentation key to the lightdm manpage
    - Disable IgnoreSIGPIPE
    - Set DBus name to org.freedesktop.DisplayManager
  + Comment out "Restart=always". X crashes too frequently to enable
    this
  + Remove "WantedBy=graphical.target"
- File: lightdm.install
  + lightdm in [community] sets the UID and GID to 620, so this package
    will transition to that by deleting the old lightdm user and group
    and creating new ones with the new IDs
  + Make sure systemd-tmpfiles is called
  + Don't check for the existance of userdel and groupdel in
    post_remove()
- File: lightdm.pam
  + Merge from AUR package lightdm-devel
  + Make sure users in the nopasswdlogin group and actually login
    without a password
- File: lightdm.rules
  + PolicyKit rules from Fedora, which allow the lightdm user to access
    the DBus interfaces for systemd's login1, consolekit, and upower
- File: lightdm-tmpfiles.d
  + Merge from AUR package lightdm-devel
- File: compare_versions.sh
  + Updated for changes to PKGBUILD