clone_image is a wrapper around newimageid_ez and create_image, that
simplifies the most common operation; creating a new imageid derived
from the image/os that is currently running in the node, and then
taking a snapshot of the node. So for example, if node pcXXX is
running image FREEBSD, and you want to create a custom image from that
node, all you need to do:

	boss> clone_image myfreebsd pcXXX

which will create the new descriptor, deriving everything from the
FREEBSD image on the node, and then take a snapshot from pcXXX. If
the descriptor already exists, just take the snapshot.

So what if you do:

	boss> clone_image FREEBSD pcXXX

well, the image is always looked up in the project the node is
currently attached to, so in fact a new descriptor is created in that
project, and you do not actually overwrite an image from some other
project. 

I've added some locking to images to prevent concurrent snapshots.
This seemed like a good idea since this script is going to be used
from the ProtoGeni interface. More on this in another commit.

appropriate action.

set the hash in the DB. This is helpful on system images where we save
the image off in /proj and copy it back later, and also for computing
the hash of the zillions of images that already exist.

Usage: imagehash [-d] [-n] <imageid>
       imagehash -p <imageid>
Options:
       -d     Turn on debug mode
       -p     Show the current hash in the DB
       -n     Impotent mode; compute hash but do not update

that we can return the tags from tmcd even if snmpit has
not created the vlan yet.

Also remove the test that requires only one new attribute at a time
Not sure where that came from.

wrapper.

Death to the wrapper.

Problem before was that I was using 'git log' of the commit and
its parent, which doesn't work as I intended when there's more than
one parent. Instead, use 'git show -s', which is helpfully not
documented in the manpage for git-show, but instead the manpage for
git-shortlog

to emulabconfig variables; this allows me to put a bunch of
passwords into a file instead of elabinelab attributes, which
land in log files, mail logs, ns files, etc.

Do not set root password to fixed string in rc.mkelab. Instead, if one
does not come in the config variables, generate a random password
string and write that into a file in /usr/testbed/etc.

Localize NAMED_VARIABLES from the config variables if it exists.

ops will boot more quickly if boss is also booting or not booted
yet.

This turns out to be less obvious then first thought, since
with PAM built into sshd, also need to turn off the
ChallengeResponseAuthentication setting.

everything figured out for setting up the private vlan on both
switches. There is a wire from eth1 on the control node to a port on
the control switch. Another wire from eth2 to a port on the
experimental switch. The complication on the control switch is that we
have no serial console, and so we actually have another wire from eth3
to the control switch, so that we can dhcp and then log in and do a
switcherroo to get the private vlan configured.