bc is marked as optional in Debian and I just hit a machine where it is
not installed. Python might be also not installed but we depend on
python in many more places so using it instead of bc reduces the
probability `neotest info-local` won't work on a fresh machine.

Similarly to 352cd100 (X neotest: Fix disk display in case of MD).

before:

    # vg0-root:   rev     74.5G

after:

    # dm-0 (vg0-root) -> sdi2
    # sdi: PERC H330 Mini    rev 4.27 111.3G

Similary to f2932247 (X neotest/info-local: Don't crash if an egg could
not be found)

before:

    # Fri, 03 Nov 2017 10:47:37 +0300
    # kirr@deco.navytux.spb.ru (2401:5180:0:37::1 192.168.0.2)
    # Linux deco 4.13.0-1-amd64 #1 SMP Debian 4.13.4-2 (2017-10-15) x86_64 GNU/Linux
    # cpu: Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
    # cpu[0-3]: freq: intel_pstate/powersave [.40GHz - 3.40GHz]
    # cpu[0-3]: idle: intel_idle/menu: POLL(0μs) C1(2μs) C1E(10μs) C3(70μs) C6(85μs) C7s(124μs) C8(200μs) C9(480μs) C10(890μs)
    # cpu: WARNING: frequency not fixed - benchmark timings won't be stable
    # cpu: WARNING: C-state exit-latency is max 890μs - up to that can add to networked and IPC request-reply latency
    # sda: SanDisk X400 M.2  rev 0012  477G
    # wlan0: Intel Corporation Wireless 8260 rev 3a
    # wlan0: features: !rx !tx sg !tso !ufo gso gro !lro !rxvlan !txvlan !ntuple !rxhash ...
    # wlan0: coalesce: rxc: ?,  txc: ?
    # wlan0: down, speed=?, mtu=1500, txqlen=1000, gro_flush_timeout=0.000µs
    # wlan0: WARNING: TSO not enabled - TCP latency with packets > MSS will be poor
    # eth0: Intel Corporation Ethernet Connection I219-LM rev 21
    # eth0: features: rx tx sg tso !ufo gso gro !lro rxvlan txvlan !ntuple rxhash ...
    # eth0: coalesce: rxc: 3μs/0f/0μs-irq/0f-irq,  txc: 0μs/0f/0μs-irq/0f-irq
    # eth0: up, speed=1000, mtu=1500, txqlen=1000, gro_flush_timeout=0.000µs
    # Python 2.7.14
    # go version go1.9.2 linux/amd64
    # sqlite 3.20.1 (py mod 2.6.0)
    # ./neotest: строка 733: mysqld: команда не найдена

after:

    # Fri, 03 Nov 2017 10:44:12 +0300
    # kirr@deco.navytux.spb.ru (2401:5180:0:37::1 192.168.0.2)
    # Linux deco 4.13.0-1-amd64 #1 SMP Debian 4.13.4-2 (2017-10-15) x86_64 GNU/Linux
    # cpu: Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
    # cpu[0-3]: freq: intel_pstate/powersave [.40GHz - 3.40GHz]
    # cpu[0-3]: idle: intel_idle/menu: POLL(0μs) C1(2μs) C1E(10μs) C3(70μs) C6(85μs) C7s(124μs) C8(200μs) C9(480μs) C10(890μs)
    # cpu: WARNING: frequency not fixed - benchmark timings won't be stable
    # cpu: WARNING: C-state exit-latency is max 890μs - up to that can add to networked and IPC request-reply latency
    # sda: SanDisk X400 M.2  rev 0012  477G
    # wlan0: Intel Corporation Wireless 8260 rev 3a
    # wlan0: features: !rx !tx sg !tso !ufo gso gro !lro !rxvlan !txvlan !ntuple !rxhash ...
    # wlan0: coalesce: rxc: ?,  txc: ?
    # wlan0: down, speed=?, mtu=1500, txqlen=1000, gro_flush_timeout=0.000µs
    # wlan0: WARNING: TSO not enabled - TCP latency with packets > MSS will be poor
    # eth0: Intel Corporation Ethernet Connection I219-LM rev 21
    # eth0: features: rx tx sg tso !ufo gso gro !lro rxvlan txvlan !ntuple rxhash ...
    # eth0: coalesce: rxc: 3μs/0f/0μs-irq/0f-irq,  txc: 0μs/0f/0μs-irq/0f-irq
    # eth0: up, speed=1000, mtu=1500, txqlen=1000, gro_flush_timeout=0.000µs
    # Python 2.7.14
    # go version go1.9.2 linux/amd64
    # sqlite 3.20.1 (py mod 2.6.0)
    # mysqld          : ø
    # neo             : ø
    # zodb            : ø
    # zeo             : ø
    # mysqlclient     : ø
    # wendelin.core   : ø

ZODB: based on 5.3.0-5-gcb928231e + y/rawext patch
zodbtools: with not-yet-in-master format stabilization + rawext

The main reson why generated files change a lot is because of this ZODB
commit:

https://github.com/zopefoundation/ZODB/commit/be5a9d54

where pickle protocol used to save data under python2 changed from 1 to 2.

before:

    # Thu, 02 Nov 2017 12:06:49 +0300
    # kirr@deco.navytux.spb.ru (2401:5180:0:37::1 192.168.0.2)
    # Linux deco 4.13.0-1-amd64 #1 SMP Debian 4.13.4-2 (2017-10-15) x86_64 GNU/Linux
    # cpu: Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
    # cpu[0-3]: freq: intel_pstate/powersave [.40GHz - 3.40GHz]
    # cpu[0-3]: idle: intel_idle/menu: POLL(0μs) C1(2μs) C1E(10μs) C3(70μs) C6(85μs) C7s(124μs) C8(200μs) C9(480μs) C10(890μs)
    # cpu: WARNING: frequency not fixed - benchmark timings won't be stable
    # cpu: WARNING: C-state exit-latency is max 890μs - up to that can add to networked and IPC request-reply latency
    # sda: SanDisk X400 M.2  rev 0012  477G
    # wlan0: Intel Corporation Wireless 8260 rev 3a
    # wlan0: features: !rx !tx sg !tso !ufo gso gro !lro !rxvlan !txvlan !ntuple !rxhash ...
    # wlan0: coalesce: rxc: ?,  txc: ?
    # wlan0: down, speed=?, mtu=1500, txqlen=1000, gro_flush_timeout=0.000µs
    # wlan0: WARNING: TSO not enabled - TCP latency with packets > MSS will be poor
    # eth0: Intel Corporation Ethernet Connection I219-LM rev 21
    # eth0: features: rx tx sg tso !ufo gso gro !lro rxvlan txvlan !ntuple rxhash ...
    # eth0: coalesce: rxc: 3μs/0f/0μs-irq/0f-irq,  txc: 0μs/0f/0μs-irq/0f-irq
    # eth0: up, speed=1000, mtu=1500, txqlen=1000, gro_flush_timeout=0.000µs
    # Python 2.7.14
    # go version go1.9.2 linux/amd64
    # sqlite 3.20.1 (py mod 2.6.0)
    # mysqld  Ver 10.1.26-MariaDB-1 for debian-linux-gnu on x86_64 (Debian unstable)
    Traceback (most recent call last):
      File "<string>", line 4, in <module>
      File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 963, in require
        needed = self.resolve(parse_requirements(requirements))
      File "/home/kirr/src/wendelin/venv/z-dev/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 849, in resolve
        raise DistributionNotFound(req, requirers)
    pkg_resources.DistributionNotFound: The 'neoppod' distribution was not found and is required by the application

after:

    # Thu, 02 Nov 2017 12:09:01 +0300
    # kirr@deco.navytux.spb.ru (2401:5180:0:37::1 192.168.0.2)
    # Linux deco 4.13.0-1-amd64 #1 SMP Debian 4.13.4-2 (2017-10-15) x86_64 GNU/Linux
    # cpu: Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
    # cpu[0-3]: freq: intel_pstate/powersave [.40GHz - 3.40GHz]
    # cpu[0-3]: idle: intel_idle/menu: POLL(0μs) C1(2μs) C1E(10μs) C3(70μs) C6(85μs) C7s(124μs) C8(200μs) C9(480μs) C10(890μs)
    # cpu: WARNING: frequency not fixed - benchmark timings won't be stable
    # cpu: WARNING: C-state exit-latency is max 890μs - up to that can add to networked and IPC request-reply latency
    # sda: SanDisk X400 M.2  rev 0012  477G
    # wlan0: Intel Corporation Wireless 8260 rev 3a
    # wlan0: features: !rx !tx sg !tso !ufo gso gro !lro !rxvlan !txvlan !ntuple !rxhash ...
    # wlan0: coalesce: rxc: ?,  txc: ?
    # wlan0: down, speed=?, mtu=1500, txqlen=1000, gro_flush_timeout=0.000µs
    # wlan0: WARNING: TSO not enabled - TCP latency with packets > MSS will be poor
    # eth0: Intel Corporation Ethernet Connection I219-LM rev 21
    # eth0: features: rx tx sg tso !ufo gso gro !lro rxvlan txvlan !ntuple rxhash ...
    # eth0: coalesce: rxc: 3μs/0f/0μs-irq/0f-irq,  txc: 0μs/0f/0μs-irq/0f-irq
    # eth0: up, speed=1000, mtu=1500, txqlen=1000, gro_flush_timeout=0.000µs
    # Python 2.7.14
    # go version go1.9.2 linux/amd64
    # sqlite 3.20.1 (py mod 2.6.0)
    # mysqld  Ver 10.1.26-MariaDB-1 for debian-linux-gnu on x86_64 (Debian unstable)
    # neo             : ø
    # zodb            : 5.3.0-6-g52d79afa3
    # zeo             : 5.1.0-11-gbd4aaf68
    # mysqlclient     : ø
    # wendelin.core   : ø

See aeeaef89 (Update comment of RECOVERING state).

* origin/master:
  neomigrate: fix typo in a warning message
  neoctl: make cell padding consistent when displaying the partition table
  storage: fix possible crash when delaying replication requests
  qa: bug found in assignment of storage node ids, add test
  Update comment of RECOVERING state
  Add support for OpenSSL >= 1.1

There it was errgroup.Group adjusted with Gox for functions with
exceptions, but exceptions usage should be constrained to tests only and
it is easy to do with just Go(exc.Funcx(...)) explicitly or via local
gox function as syntax sugar.

Tests could be now run from any dir.

it was e.g.:

	lsblk: /dev/md: not a block device
	lsblk: /dev/md: not a block device
	# md:   rev

now:

	# md1 (raid0) -> sda3  sdb3
	# sda: SAMSUNG MZ7LN256  rev 100Q 238.5G
	# sdb: SAMSUNG MZ7LN256  rev 100Q 238.5G

The problem with `getent hosts ...` is that /etc/hosts has to be
manually prepared for it to work and it just does not scale and is error
prone.

So just extract machine global IP addresses at runtime as configured on
the interfaces.