Changes to the "auto nice daemon" so it can work better in Emulab.

  * sensors/and/GNUmakefile.in: Emulab-specific make file.  Updated to
    work with a build tree separate from the source and gave it a new
    version number. Files are installed under "/usr/testbed/" on ops.

  * sensors/and/Makefile: Add a warning that this is not the real
    makefile for us.

  * sensors/and/and-OpenBSD.c: Update to work with FreeBSD and add
    support for reporting process start time.

  * sensors/and/and-emulab.conf.in: Emulab-specific configuration,
    similar to the standard one, except it sends mail to tbops when it
    does something.

  * sensors/and/and-emulab.priorities: Emulab-specific priorities
    database. It excludes daemon pseudo users and the event-scheduler,
    otherwise, niceness levels apply to everyone.

  * sensors/and/and.8.man: Add the pid file to the 'FILES' section.

  * sensors/and/and.c: Added support for running a command when a
    niceness level change occurs.  Also writes out the pid file when
    not running in test mode.

  * sensors/and/and.conf.5.man: Add docs for the level commands.

  * sensors/and/and.h: Add start time and child CPU time to the
    and_procent struct.

  * sensors/and/and.startup: Changed to use "test" instead of bash
    syntax and the pid file is now used instead of killall.  Also
    added a "reconfig" option that HUPs the daemon.