Linux console handling improvements for Hardy

The switch to console-setup in 6.10 went quite well, but our console handling needs some further improvements. We should switch to kbd to fix some corner cases in font handling. console-setup needs internationalisation. loadkeys no longer has a simple equivalent (#83487).

The console font is often not restored when switching back from X. Apparently (daniels) this is the driver's responsibility, usually implemented with vgaHWSave/vgaHWRestore since the Linux-specific ioctls break in the multi-card case and are slower for some cards; but it still seems to be breaking so we need to look over this.