Revamp the inuse script
Revamp the inuse script

I use the script all the time (I'm probably the only one), and was
tired of it not being very good for answerint the questions I wanted:
how many nodes are there in holding experiments, how long have they
been there, limiting to specific types, etc.

Add a bunch of command line options to limit to specific node types,
projects, etc. Also added the ability to display free nodes (somewhat
redundant with 'avail', I know), and sort by different columns
(such as the time the reservation started).

Default to only PCs - too much noise otherwise.

Print only useful columns from the database.

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