Save state during install for FC6

[Sherwood Botsford <sbotsford sjsa ab ca>]

Scenario: You boot from CD, you answer several screens of 
questions, you start the install. 3 cd's later it borks. Back to 
square 1. There is no meaningful way to pick up the pieces.

Principle: The system should become bootable as early as possible.
Principle: The state of all your decisions should be saved as 
early as possible.

Ideally then if it borks on CD #3, you should be able to go away, 
burn a new copy of CD#3
come back, start with #1. On startup, Anaconda sees that there is 
a file in the root file system called /install-status. Pop-up:
"It appears that a previous installation failed. Would you like to:
  <<*>>Try to continue the failed install.
  <<*>>Start again."