Convert most SNMP interaction to use the snmpit*() library, so that
they get support for retrying failures, etc.

Add new library calls for wrapping bulkwalk() - so now, we will
retry those on error as well. Before, we had the bad behavior than
many functions, like listVlans() would just see empty lists instead
of errors.

When making a new Cisco object, we now test network connectivity right
away, by fetching an OID that should exist on all SNMP devices. Before,
we wouldn't find out we couldn't contact the switch until we actually
did something on it.

Also, make VLAN number choosing go a bit faster by converting it to
bulkwalk() (using the new library function) so we can grab all VLAN
numbers at once.

we're going to remove. We used to do all VLANs in one lock for
performace reasons - however, I'm discovering that the lock can get
held for such a long time when many VLANs are being deleted that other
VLAN operations, such as listing VLANs, can fail. And, it's not
actually that much slower to grab a new lock each time.

they don't by default destroy the partially completed project request data
in the form.

Produces a different message in the web page.

Also fix up a couple of minor firewalled elabinelab issues.

run before the main timeline is started.  Also changed the scheduler
to load events before adding the TIME START events so we can add setup
events before the main timeline.

* Add libadminmfs.pm with routines for entering/exiting and executing
  commands in, the admin MFS.  Node admin and firewall swapout (see
  below) now use this, the image creation process does not yet.

* Add swapout time hooks for running an admin mode process, likely to
  be used to collect swapout time state.  Currently controlled globally
  by two new sitevars.

* Modified node_admin to use the library and added a "-c <command>"
  option to have nodes go into admin mode and run a command.  I don't
  really expect this to be useful, it was just a testing vehicle for
  the library.

2. Improved the swapout process for firewalled experiments.  Largely
   just generalized what we already did for paniced experiments.
   At swapout, firewalled nodes are:

   - powered off
   - set to boot into admin mode and run a disk zapper
   - powered on

  The swapout process then waits for all nodes to successfully complete
  disk zapage, at which point the nodes are nfree'ed as usual.  Any
  failure of the above process, marks the experiment as panic'ed (to
  ensure that we are involved in cleanup) and sends mail to testbed-ops
  describing the state of the nodes.

3. Added the aforementioned disk zapper, a little C program in the MFS
   which zeroes out the MBR and partition boot blocks (but not the MBR
   partition table or FS superblocks).  This is added insurance that if
   a node somehow gets diverted after being nfree'd but before getting
   the disk reloaded (e.g., goes to hwdown), that we cannot accidentally
   boot from the disk.  This program gets installed in the admin MFS.

4. Related to firewalls, modified swapin to use the new documented
   "snmpit -N" to get the firewall VLAN number rather than parsing the
   output that was a side-effect of VLAN creation.

This is a cheap verification mechanism.  Also install imagehash now with
all the other image tools, it will be used soon.

Factor the Cygwin password authentication hack out of program-agent into libtb, and use it in linktest as well.

The options (HAVE_* enviornment settings) have been there for awhile,
I just found a way to set an environment variable from the makefile.

making into the eventlist.

but probably going to mangle everything again when I get back.

directories to download and where to put them locally.  Also added -n
flag to exclude the default directories from the download.

Check this in now to prevent problems for others.

of traffic going over the link.  We also create a custom config file
for our hacked version of gkrellmd that contains the mappings from
interface name to node/link name, so it's easy to see which interface
corresponds to a particular link.

we allow through our cisco ACLs.  If someone uses our acls without this,
NFS won't work.

Will only affect the MFSes and other internal uses, does NOT impact
user specified start commands.

box stops after a while, so that the user is not kept logged in
forever.

Correct a few errors/omissions in README.

Tweak log output.

Add "priorities" to exported_tables in libtblog.sql.

start,swap,swapmod,terminate.