Part of my changes to support swapmod of ElabInElab experiments. I needed

to get this change in cause it also includes some DHCPD conf changes and
Mike and I were messing each other up.

* The DHCPD change is that instead of using reserved.inner_elab_role
  as the flag to indicate a node should boot inside or outside, I
  added inner_elab_boot, which is a boolean that I set when its
  actually time to do this. This avoids two ElabInElab swapins at the
  same time from messing each other up! Basically avoids the obvious
  race.

* The rest of the changes are for swapmod itself, which are incomplete
  but should be harmless until the rest of the stuff is ready.