When we have a section to generate a python interpreter with eggs built
in, don't name this `extra-eggs` because the meaning is not clear.

Despite the name, this section was inherited from monitor, but now that
we fixed monitor to prefix the sections, this section is no longer
extended from monitor, but defined in softwares

NBD server is not running until an image is uploaded. Make sure that the
promise doesn't fail until the image is there. Also display a WARNING in
the connection parameter to say that the NBD server is not running.

The OS may not have Python (slapos-node package does not depend
on any version of Python). Another possible issue was found on Suse:

  make[3]: Entering directory '.../parts/glib__compile__/glib-2.56.4/gio'
    GEN      gdbus-daemon-generated.c
  Traceback (most recent call last):
    File "./gdbus-2.0/codegen/gdbus-codegen.in", line 53, in <module>
      from codegen import codegen_main
    File ".../parts/glib__compile__/glib-2.56.4/gio/gdbus-2.0/codegen/codegen_main.py", line 30, in <module>
      from . import parser
    File ".../parts/glib__compile__/glib-2.56.4/gio/gdbus-2.0/codegen/parser.py", line 23, in <module>
      import xml.parsers.expat
  ImportError: No module named xml.parsers.expat

Real frontend is always requested.

Additional frontend is requested only if frontend-additional-instance-guid is
not empty. This frontend is published as url-additional and can be used for
access to users from some restricted networks.

  Remove duplicated version definition at software level to prevent excessive duplication
  of the value.

- Add `buildout.hash.cfg` file so this way we can use the useful `update-hash` script
- Refactor a bit the `software.cfg` file sections as it was repeating itself

/reviewed-on nexedi/slapos!512

If qemu use physical disk device instead of created qemu image disk, we skip this promise.

/reviewed-on nexedi/slapos!507

They are dependencies of slapos.toolbox and we already agreed to put slapos.toolbox version in a shared file.

/cc @jerome @jm

/reviewed-on nexedi/slapos!502

Use tap information from partition resource (coming from slapconfiguration recipe) instead of old (and deprecated softwaretype recipe).

This way when setting `udp:<port>` in `nat-rules` instance parameter, it won't mess up with buildout's syntax.

PS: It seems the UDP won't work at all since `6tunnel` doesn't support TCP tunneling, so this is more of a cosmetic fix.

/reviewed-on nexedi/slapos!464

/reviewed-on nexedi/slapos!456

/reviewed-on nexedi/slapos!427

  Sticky computer on kvm cluster, will make the requester (root instance on this case), request
  the children on the same computer as itself.

Set cache.direct=on when using native aio (needed by qemu)

/reviewed-on nexedi/slapos!399

  Allow the KVM software release request a disk via plugin,
  if the plugin is enabled the chown will be set to give the disk to the partition.

/reviewed-on nexedi/slapos!380

  it  clean up....

  Up to some extent we would like to set diskcache=none and diskaio=native