Allows requesting a caucase partition and reusing an existing caucase instance.
For client-certificate-based authentication, client must be able to access backend
directly (frontend is not possible).

This simplistic mail setup does not pass address as command line arguments,
so it is not subject to the vulnerability protected against by this option.

Whitespaces matter to exporter.exclude:
- patterns must *not* start with a space
- file *must* end with a newline

Also, de-duplicate paths.

Makes it easier to deploy a functional replication setup.

software/erp5 & stack/erp5: Add a new parameter wendelin-core-zblk-fmt. Use it to specify wendelin.core format(ZBlk0 or ZBlk1).

Use a special milter to do what postfix cannot do with its internal
mechanisms.
- fixes postfix-generated bounces so they reach postmaster mail address
  without being rewritten
- actually makes postfix relay rewritten mails (virtual_alias implicitly
  affects virtual_domains, in turn making all mail addresses considered
  locally hosted, which cannot and must not successfully deliver)
Also, backport a yet-unreleased-but-already-upstreamed patch fixing
rcpt value truncation, which breaks when recipient address is not
enclosed in angle brackets - making the mail still reach original
recipient.

Disable more mariadb options during backup restoration:
- relax durability
- disable binlogs
- disable slow log
Bits of this commit were already accidentally (but harmlessly) pushed as
part of
  commit 5bde847f
  Author: Vincent Pelletier <vincent@nexedi.com>
  Date:   Tue Feb 21 16:02:21 2017 +0900

    stack.erp5: Avoid duplicating mariadb service paths.

This way, processing nodes are sorted the same way as the node ids, making
cross-referencing easier.

Prevents a few possible accidental variable expansions and space
susceptibilities.

When a process is stopped:
- it may not have emitted logs since previous rotation: add "missingok"
  As a direct consequence: stop using logrotate recipe.
- its pid file (if applicable) may be missing: test its non-empty presence
  before calling slapos-kill
Also, stop using slapos.cookbook:logrotate.
Update obvious users (cloudooo, neoppod, erp5, monitor, re6stnet).

Will be needed to customise backup restoration.
Also, stop using slapos.cookbook:generic.mysql.wrap_mysqld, which:
- did not allow extra arguments
- did incorrect and superfluous ulimit manipulation

Also, move instance-mariadb-resiliency-after-import-script.sh.in out of its
subdirectory, as it causes problems when passing the "filename" option to
slapos.recipe.build:download recipe.