Move the expiration test into verifygenicred. Change the invocation to
capture the output so that we can say something useful in the error
response, instead of what we do now which is just tell the user there
is an error.

as ports come and go.

(like os_load does).

This is in preparation for allowing a comma separated list with more
than one imageid.  Also change sched_reload.in accordingly.

In error message change "$:" to "$0:", which I am 99.9% sure what was
intended.

This call allows a geni user to create a sliver, customise the node,
and then take a snapshot (possibly creating a new image descriptor)
without having to use the Emulab web interface. The API looks like:

  int CreateImage(slice_urn, sliver_urn, imagename, credentials[]);

The slice must be unlocked and the sliver in the ready state. Once
the operation starts, the slice is locked until the backend finishes.
This is something that I might revisit later, but this was the easiest
approach that ensures consistency. 

The imagename is looked up in the current project the node is attached
to. If it does not exists, create it. Then snapshot the node. You can
call this again of course, to take a new snapshot, without having to
provide a new imagename.

The image file is written to the images directory of the project,
which is available to the node via /proj, so the user can get to it
(since the user might not have a local account).

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.