pstree: It works... it actually works!

Lots of learning along the way and realizations that Rust's manual
memory management actually prevents you from doing bad things that
you might otherwise want to do.  Fair enough.  Lots of syntactic struggles
and wishin the language was managed at times.

- / #0
  - init #1
    - upstart-udev-br #295
    - systemd-udevd #303
    - upstart-file-br #391
    - rsyslogd #443
    - dbus-daemon #499
    - upstart-socket- #507
    - ModemManager #579
    - bluetoothd #581
    - systemd-logind #593
    - avahi-daemon #686
      - avahi-daemon #688
    - NetworkManager #777
      - dhclient #1046
      - dnsmasq #1060
    - getty #859
    - getty #863
    - polkitd #899
    - getty #904
    - getty #905
    - getty #908
    - sh #931
      - initctl #944
    - sshd #981
    - kerneloops #1000
    - cron #1006
    - acpid #1018
    - cups-browsed #1023
    - whoopsie #1054
    - VBoxService #1210
    - getty #1276
    - lightdm #1295
      - Xorg #1319
      - lightdm #1340
        - mate-session #1355
          - ssh-agent #1446
          - mate-settings-d #1541
          - marco #1545
            - zenity #8779
          - mate-panel #1549
            - mate-terminal #1864
              - gnome-pty-helpe #1873
              - zsh #1874
                - pstree #15186
                - emacs #13667
                - pstree #15186
              - zsh #7803
            - java #8648
          - caja #1558
          - polkit-mate-aut #1587
          - deja-dup-monito #1589
          - indicator-power #1593
          - indicator-bluet #1594
          - update-notifier #1600
          - zeitgeist-datah #1607
          - nm-applet #1613
          - applet.py #1623
    - accounts-daemon #1305
    - VBoxClient #1423
    - VBoxClient #1431
    - VBoxClient #1436
    - VBoxClient #1441
    - dbus-launch #1450
    - dbus-daemon #1461
    - ibus-daemon #1476
      - ibus-dconf #1493
      - ibus-ui-gtk3 #1494
      - ibus-engine-sim #1570
    - gvfsd #1488
    - ibus-x11 #1498
    - gvfsd-fuse #1503
    - dconf-service #1509
    - gnome-keyring-d #1522
    - at-spi-bus-laun #1528
      - dbus-daemon #1532
    - at-spi2-registr #1535
    - pulseaudio #1561
    - rtkit-daemon #1563
    - gvfs-udisks2-vo #1572
    - udisksd #1581
    - upowerd #1599
    - gvfs-mtp-volume #1630
    - zeitgeist-daemo #1634
    - gvfs-gphoto2-vo #1639
    - gvfs-afc-volume #1671
    - zeitgeist-fts #1708
      - cat #1789
    - wnck-applet #1767
    - notification-ar #1769
    - clock-applet #1771
    - gvfsd-trash #1792
    - gconfd-2 #1798
    - cupsd #1858
    - gvfsd-burn #8225
    - geoclue-master #8247
    - ubuntu-geoip-pr #8251
    - gvfsd-http #8281
    - master #11380
      - qmgr #11383
      - pickup #13717
    - notify-osd #11677
    - gnome-screensav #11715
    - gvfsd-metadata #13196
    - oneconf-service #15144
  - kthreadd #2
    - ksoftirqd/0 #3
    - rcu_sched #7
    - rcuos/0 #8
    - rcuos/1 #9
    - rcu_bh #10
    - rcuob/0 #11
    - rcuob/1 #12
    - migration/0 #13
    - watchdog/0 #14
    - watchdog/1 #15
    - migration/1 #16
    - ksoftirqd/1 #17
    - khelper #20
    - kdevtmpfs #21
    - netns #22
    - writeback #23
    - kintegrityd #24
    - bioset #25
    - kblockd #27
    - ata_sff #28
    - khubd #29
    - md #30
    - devfreq_wq #31
    - khungtaskd #33
    - kswapd0 #34
    - ksmd #35
    - khugepaged #36
    - fsnotify_mark #37
    - ecryptfs-kthrea #38
    - crypto #39
    - kthrotld #51
    - scsi_eh_0 #54
    - scsi_eh_1 #55
    - deferwq #76
    - charger_manager #77
    - scsi_eh_2 #118
    - kpsmoused #122
    - kdmflush #138
    - bioset #139
    - kdmflush #140
    - bioset #141
    - jbd2/dm-0-8 #157
    - ext4-rsv-conver #158
    - ext4-rsv-conver #341
    - iprt #422
    - krfcommd #694
    - kauditd #1345