remove code to mount /live/lib/splash/{sys,proc}

It was broken and when it was fixed it just made things worse
Umount /live/lib/splash/proc if it is a mountpoint

Work around a bug in fbcodecor_helper when there is a "vga"
parameter but no "splash" parameter.
Modify live-init to try to stay on tty1

Fighting against fbcondecor_helper when vga is given
but splash is not.