Summary: This closes T178.
Test Plan: Looking at the splash screen during boot and shutdown, the logo should be centered.
Reviewers: wxl, tsimonq2
Maniphest Tasks: T178
Differential Revision: https://phab.lubuntu.me/D56
* Transition with new plymouth from /usr/share to /lib:
- replace /lib instances by /usr/share
- move src/lib/plymouth to src/usr/share/plymouth and adapt Makefile
- breaks against older plymouth.
- ensure we can transition the alternatives to the new version