See these pages:
https://launchpad.net/ubuntu/+source/lightdm/1.6.0-0ubuntu2.1
http://www.ubuntuupdates.org/package/core/raring/main/proposed/plymouth
It looks as if changes to lightdm.conf have outstripped changes to plymouth.
See these pages:
https:/ /launchpad. net/ubuntu/ +source/ lightdm/ 1.6.0-0ubuntu2. 1
http:// www.ubuntuupdat es.org/ package/ core/raring/ main/proposed/ plymouth
It looks as if changes to lightdm.conf have outstripped changes to plymouth.