Assorted changes.
Assorted changes.

Add wait option (-w). Check for lots of things that could have occured
while waiting and abort if such things happened (since any number of things
could have happened to the lease while you slept).

Permit state transtions that alloc/delloc resources if -R is specified.
Add -U option to forcibly unlock a lease (if it somehow got left locked).

nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome