Pick lots of fixes from upstream up to v36.
A few features added too:
- support more types of virtual serial consoles in getty-generator
- log control via RT signals
- support for LANGUAGE in environment
- show fsck progress on the console
Fixes: BZ#735013, BZ#722803, BZ#736360, BZ#698198, BZ#710487
Fixes: fdo39957, fdo39818, fdo40510