/etc/rc.early is no longer supported so we set it in /boot/loader.conf instead.

Also, get group/passwd files back in sync with 7.3 release.

Note to self: change DB so that the default sshdport for nodes is null
instead of some silly value like 11000.

port to a vnode. This can lead to confusion in the experiment if the
user does not reboot all the nodes. This fix turned out to be more
complicated then I thought, and I have not figured out how to apply it
to trafgens port numbers.

experiments, even on other testbeds. This is because snmpit -o does
not untrunk ports, and I do not have time to fix this now. Without
this change, the shared nodes holding experiment cannot be changed.

This is part of cleaning up the name space of pubsub.  Previously, this
program was getting the "info" call from libpubsub and that version is going
to become private.  So use the one in libtb instead.

Includes hack to "fix" upstart dependency problems:

A) eth* interfaces are probed by ifupdown serially instead of in
   parallel.
B) Legacy initscript support waits for the the control net probe
   to finish (with either success or failure) before running legacy
   initscripts.

The stand-alone desktop client is no longer supported - the GUI applet
is nearly as good (just doesn't allow user to ssh to the nodes), and
actually works.

Contributed by IBBT/UGent

  As you can see, most of those are in use even during our
  periods of "light" usage.
At Mike's request since "it isn't true now.  It will probably be true
again, but it will take awhile..."

That is when more than a fixed threshold of nodes (0.05 for now) are
in an invalid state for any particular class (ie "pc3000s", "d710s",
etc) only invalid that class for the time period, instead of all the
plot data.

Along the way fix various bugs with handling NaN (how invalid states
are flagged).

to avoid running out of memory.

a link or lan fall on a shared node. I messed up the test in a
previous commit.

around; Remove the trac ticket link and replace with a pointer to
the emulab-users help forum.