Link detection/DHCP rework committed

[Dan Williams <dcbw redhat com>]

Hi,

I just committed the new link detection/DHCP rework code.  I'd like 
everybody to pull it down and test it out.

Major benefits:
1) Works with Open System auth mode
2) Seems fairly quick for most situations
3) Less complicated code, easier to understand

Note to system backend people:

Its not actually using any DHCP stuff anymore.  I didn't actually remove
any of the functions in the backend files, but DHCP stuff there isn't 
called.  We need to test out the integrated DHCP stuff and make sure that 
works for people with as many DHCP servers as possible.  Debugging is 
turned on for the DHCP client code at this point, so it should be fairly 
easy to figure out what's going on when using --no-daemon from a console.  
NetworkManager is now setting the following things itself in response to 
DHCP responses: a) ip address, b) netmask, c) broadcast address, d) 
resolv.conf.

At this point, the DHCP stuff isn't totally complete.  The work to be done 
on the DHCP side includes:
a) Renewal of leases after T1, rebinding of the address after T2
b) Reboot state, try to use last IP address, though this would require 
storing that IP address somewhere in GConf or whatever
c) Completion of the DHCP state engine stuff

Dan