bug#26970: plymouth

[ng0]

This patch adds plymouth, the early bootprocess daemon.
It provides a 'boot splash'.

Users will not install this on their own (or be able to
use it freestanding) which is why we need at least a
system-service for this.

I'd hate to be the bottleneck for this, so here is my work
from back in december (builds okay!).

According to Gentoo, we will need to apply changes to the
GRUB menu and are advised to disable the linux boot logo
display (https://wiki.gentoo.org/wiki/Plymouth).

I also advise like we concluded in a chat in december,
that we write a system test for this.

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0001-gnu-Add-plymouth.patch
Description: Text document