To add a Database, user should request a slave instance. Each slave
instance is a database.

TODO: Destroy a slave instance should destroy related database

With recently backported fix for h5py

This software uses xml for parameters serialisation, so we can not use
boolean type. As a result, smtp_verify_ssl was always "true" and disabling ssl
verification was not working.

When accessing the smtp server from localhost, grafana attempt STARTLS and
verifies certificate, so scenarios of using localhost:25 as smtp server usually
needed smtp_verify_ssl="false".

Fixes and tests https://github.com/apache/trafficserver/issues/7880

By following:

https://docs.trafficserver.apache.org/en/9.0.x/release-notes/upgrading.en.html

configuration has been adapted.

Tests to new version string has been adapted with smaller fixes, including a
bit more time for log to appear in squid.log.

Previous patch is incorporated with 4f6bfe439e4ed7794992e16c16eb991976a3018e

The missing run was hidden by slow Caddy warmup procedure.

Remote-User header is not managed by the frontend.

for https://github.com/grafana/loki/issues/3177

While investingating this, I realized loki officially supports golang 1.15, but
beside this, everything seems to work fine, so let's keep using 1.16

* version up
 * ssh keys support
 * mod_auth_web support

See merge request nexedi/slapos!993

This is a workaround to avoid the UnicodeDecodeError that occurs
when installing wheel, in particular during compilation of ERP5.

The previous way to initialize ~/srv/mariadb relied on /bin/mv, so that
it's atomic, making [template-mysqld-wrapper] idempotent (think of a
crash in the middle mysql_install_db). However, mv only works if
~/srv/mariadb is a simple directory: it fails if it's a symlink,
a mount point, or a subvolume (btrfs).

When using extra storage devices for some data, one may prefer to only
put the data (e.g. ~/srv/mariadb) and not the whole slapos partition.
Then if we want a resilient ERP5 with catalog's datadir on a separate
storage device, the importer script must be able to reinitialize
~/srv/mariadb whatever its type.

The web service will receive a application/x-www-form-urlencoded POST request,
with login and password arguments and must respond with a
`X-Proftpd-Authentication-Result: Success` header to signal successful
authentication.

The sftp server will map all logins to the same user.

This software uses xml

Switch to using official repository, now that the pull request have been
finally merged.

See merge request nexedi/slapos!983

Previous version caused a segmentation fault when running git

See merge request nexedi/slapos!906

With tesseract v4.0.0-beta.3 we often observe crashes with:

```
contains_unichar_id(unichar_id):Error:Assert failed:in file ../../src/ccutil/unicharset.h, line 511
```

This seems to have been fixed by https://github.com/tesseract-ocr/tesseract/pull/1954

Still, even after updating to 4.1.1, text recognition from PDF in ERP5 is too expensive. We also update Ghostscript to 9.54.0, because this version has built-in OCR, which does not need to convert the PDF to PNG then TIFF as we currently do in ERP5.

See merge request nexedi/slapos!985