Custom plymouth theme

In feature/tails-plymouth-theme branch we use a custom plymouth theme that looks close to windows vista bootup. So I consier "The Tails boot splash screen should be black with a tiny dots-based progress bar" as pending. It however is working only on machines with KMS-enabled graphics drivers. On other machines it falls back to the old text plugin. This was shipped in 0.12, proved to break the boot on far too many kinds of hardware, reverted in 0.12.1.

We should:

1. Reintroduce this in experimental, without enabling KMS on more hardware this time. code
   #* basically done in feature/tails-plymouth-theme
   #* we also need to install plymouth-drm
   #*# either built from our custom 0.8.3-20~bpo60+1 backported source package, that’s worth trying first
   #*# or from Wheezy’s source package (on top of it, we probably want to cherry-pick fixes for Debian bug #691598, Debian bug #683764, Debian bug #691794, Debian bug #695706 and Debian bug #683763 like Progress Linux does
2. Test it on various hardware for a while.

(This was part of implementing windows theme (#5867 (closed))).

Related issues

• Related to #6460 (closed)
• Related to #5867 (closed)
• Related to #7394 (closed)
• Related to #5417 (closed)

Original created by @tails on 5948 (Redmine)