drop support for text mode plugins?

[Peter Robinson]

Hi Ray,

> As you all know, if plymouth can't get a graphical splash up it falls
> back to doing ascii art animations.  (Either the 3 racing, overlapping
> progress bars, or the three blinking dots).  That was important when
> plymouth was started because KMS wasn't widely available.
>
> The landscape has changed fairly dramatically in the intervening
> years, and I think i'd like to drop support for these kinds of boot
> splashes.  Instead, the choices will be "graphical splash" (normaly
> situation) or "details" (show all boot messages) with nothing in
> between.  This would allow me to cut out a bunch of code from the
> codebase and simplify handling of text mode and serial consoles.
>
> Objections? Thoughts?

Seems sane, does this allow better support for serial console and
things like inputting of encryption passwords on text consoles would
be great. This is a problem we see on arm/aarch64 [1] on serial
consoles quite a bit on Fedora at least.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1172740