tree mode.

a little bit to avoid a race at the very end of time, when trying to
unregister a sliver from the SA.

... we don't do it for any other error, and it's best not to inject
user input back into the HTML page; presumably totally bogus strings
could evaluate to 0, and thus look 'too small'

It's best not to echo any form input back into the page without
cleaning it first, and in this case, it's not that important to
the message.

Also fix the conditional that was causing it to not
get printed.

Add "-Q <interval>" option to the master server to allow it to act as an
IGMP V2 querier in environment where there is otherwise not one. It does
essentially what the perl-based querier (code.google.com/p/perl-igmp-querier/)
does, sending out a v2 membership query at the specified interval.

This eliminates the need to run mrouted in some environments (e.g., elabinelab)
just to issue IGMP queries. As a result, all the boss-install and elabinelab
setup related to using mrouted to perform this function has been removed.
The elabinelab CONFIG_MROUTED option has been changed to CONFIG_QUERIER
(the former is still recognized and mapped to the latter). The undocumented
defs-* variable NEEDMROUTED has been changed to NEEDMCQUERIER (the former
still exists in install/installvars.pm.in but is always set to 0) to more
accurately reflect the variable's purpose. If NEEDMCQUERIER is set, then
the mfrisbeed startup script is modified to add the "-Q 30" option.

The implementation of the client and server "-K <interval>" keep-alive option
has been changed to directly send IGMP v2 membership reports containing the
associated MC address.

Note that the -K options have always been a hack to work-around assorted
IGMP-related misconfigurations and incompatibilities, and really should
only be used as a last resort. As implemented, they could cause the host
machine to be pruned out of other MC groups at the nearest switch since
they only report membership in the frisbee MC group. With the master server
acting as an IGMP querier, instances of the frisbee server on that host
should no longer need to do keep alives. We still have one case where it
is needed on the client-side: a FreeBSD 8.x or later host connected to an
IGMPv2-only switch. It appears that the IGMPv3 implementation added in
FreeBSD 8.x always sends v3 reports, even when the default is configured
(via sysctl or even recompiling the kernel) as v2.

Renamed the library to power_apc.pm since it has nothing to
do with snmpit, and it fooled me, and I don't want to be fooled
again, cause you know what means.

We did not allow people to change the passphrase on an existing
key, so add a form and change the backend script to allow it.

Also fix bug that was causing old sslcert derived ssh keys
to be left around.

mapVlansToSwitches to was dropping a switch when the "path" consisted
of a single switch. This solves the problem with createVlan trying
to access a switch that is not in the stack (undefined value in
dereference).

This is going to cause some bloat, will revisit later.

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.