if backup.signature is present in tmp/ folder (during push) promise will fail because find return 2 elements and 1 is expected

If pull is running, files can be changed and promise will raise. Wait when backup pull
is not running before check signature diff.

Strip earlier, as stripping so late leads to correct self.passwd
but incorrect passwd, thus 3rd party applications storing passwords
with additional newlines are still resulting in bad passwords.

/reviewed-on nexedi/slapos!366

This is a follow-up of commit 30c5367a

We still don't depend on neoppod[storage-importer,tests]
to avoid pulling ZODB3.

This also fixes pinning issue for software-zodb3.cfg

The backend url can come from request in `url` and `https-url` strings.
It is validated using real caddy template configuration and by using
caddy's `-stdin`. It results with calling it on each slave having any of
those parameters.

This reverts commit 1c9075a1.

The changes will be done on slapos.toolbox/runner to always create missing proxy.db file

add PyWavelets, decorator, networkx
version up: Pillow 5.2.0

Add osd trainned data

This is required starting erp5.utils 0.4.51

Also add a missing md5sum for instance.cfg.in

/reviewed-on nexedi/slapos!362

Fixes:

 * skip tests for parts which won't be fixed
 * fix assertion for master partition
 * fix typos
 * parameterize headers depending on frontend type

This reverts commit 8e24f3ab.

QUIC has issues with client certificate authentication, detected by chance.

  As this is used by the tests.

  As this is used by the tests.

If the version is unpinned, the buildout will fail. It is currently mandatory to
  keep all the eggs pinned.

  Any development environment can se allow-picked-version to true if they were tryting to check
  upgrades of some eggs.

This were already discussed and agreeded and the test already passed:

[20180611-4AD45F1D](https://nexedijs.erp5.net/#/test_result_module/20180611-4AD45F1D)

/cc @jerome @jm 

/reviewed-on nexedi/slapos!363