Adapt all promise sections to changes in plugin promise recipe.

Change all `check_port_listening` promises to `check_socket_listening`
and rename all associated `config-hostname` arguments to `config-host`

Install setuptools_scm before python-dateutil (which has it in setup_requires) so that the version can be controlled by buildout

See f1e7230e

slapgrid is the old name of slapos node command.

done with:

     npm install
     git ls-files | grep -v '\/unstable\/' | xargs ./node_modules/.bin/eclint fix
     git ls-files | grep buildout.hash.cfg | xargs ./update-hash

For some SR, it implies the following upgrades:
- decorator: 4.3.0
- gitdb2: 2.0.5
- smmap2: 2.0.5
- subprocess32: 3.5.3

This fixes a regression in commit a7a36453
("Clean up some zc.recipe.egg sections installing the same scripts/interpreter").

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

/cc @jerome @jm

/reviewed-on !502

 * keep the start date
 * don't remove the file before writing in it (use > directly) so that the file always exist
 * format the date with ISO 8601
 * format all the lines the same way

This will let the monitor promise read this file easily

The recent changes in rdiff backup are not backward compatible.

@tomo @rafael if you have any review on this (should be ok as its kind of same commit than last update one, but well)

/reviewed-on !433

This release should be now stable enough for release

/reviewed-on !391

This reverts commit 9b3dfa01

  This version contains optimisation for restore (and a bit for backup), specially in case of large sets of unmodified files.

Replace dropbear by openssh.
Use same rdiff-backup than provided by PBS.
Allow to directly use an IPV6 address with a custom port.