Trying new, supposedly, better mechanism to bootup iPXE and obtain DHCP.  Using ifopen should allow the device to retain and continue using the IP it picked up during the initial phase rather than trying to get a new dhcp request.  If for some reason that fails, it will attempt re-initialization.  If for some reason that re-initialization fails it will reboot the system.  Hopefully we should alleviate the reboot loop issues people have on occasion.

git-svn-id: https://svn.code.sf.net/p/freeghost/code/trunk@2762 71f96598-fa45-0410-b640-bcd6f8691b32