Implemented using libuserhosts. Only provided to zope processes so far, may be
extended in the future with each process seeing different sets of aliases,
with potentially different resolutions.

Also, do not tolerate missing instance-count internal zope partition
parameter.

Also, remove dead section "cluster".

also cleanup pt-* commands in mariadb instanciation.

1.7.1 contained a bug which broke statistical profiling in ERP5.

Reason for not using postonly instead is that anonymous persistence may be
good in some erp5 use cases (ex: shopping cart), and also authentication
cookie may outlive haproxy cookie and may lead to no persistence afterward.

Fix spurious newlines being emitted, breaking published values.
Also, remove unneeded whitespace trimming on "else" statement.

Allow creating databases without associated user account.
Do not document this, as it is part of a yet-incomplete feature.

MySQL changed the default value 3 times since 5.1, causing a waste of disk
space when recreating schemas (tables move out of an already large system
tablespace, which cannot be easily reclaimed).
Also, per-table option fragments free space: if a table shrinks, freed
space cannot be used by another table without recreating shrunk table
(which induces at least a write-lock during data copy, which may not be
trivial).

Remove non-needed parameters, empty unused parameter.
Move "inituser" closer to "user" and "password", as they are related.

When there are many ZODBs, this command can exceed crond's maximum 1024
bytes limit.