erp5-cluster: haproxy, move generic configuration into default section

This reverts commit 00ccb27d.

MDEV-6449 was fixed in version 10.0.14
Note however that TokuDB remains automatically disabled when building MariaDB
with GCC < 4.7

For NEO, TokuDB seems to be a better choice than InnoDB.

Forgot to update parameter schema.

One thread is just too limited to produce a usable instance (for example,
a single-zope setup with default thread count fails to run live tests). It
is also not an advised setting for activity nodes, because of timerserver
still queuing process_timer calls while CMFActivity is busy processing; the
result being a (limited) waste of memory, and hammering mysql after long
processing periods.
Zope's default value must be duplicated because thread-amount is also used
to generate haproxy configuration file (so just not providing the value in
Zope's configuration file is wrong).

Compatibility with runner config is to be checked

If disk is mounted in folder like /data/data* and formated by slapformat
as /data/data*/slappart* for each partition, create a symlink
instance_root/DATA/data* to allow process of partition to write in
in the mounted disk.

Set tap network information in a dict if they are defined