This plugin turns a SPADS instance into a highly configurable manager of
clusters of SPADS instances, auto-scaling to the players' demand and offering
on-demand private hosts. Each cluster is associated with a SPADS global preset
which is used for all the instances of this cluster. The cluster manager can be
used in mono-cluster mode (all the instances are in the same cluster and thus
use the same SPADS preset) or in multi-cluster mode (several clusters are
managed at the same time, each cluster having its own SPADS preset for all the
instances it contains). For information regarding cluster parameterization,
refer to the "ClusterManager.conf.README" file.

Auto-registration of lobby accounts:
-----------------------------------
If the lobby account used by the cluster manager instance has lobby server
admin access, then the required bot accounts for the slave instances can be
automatically created on the fly by the manager, as they are required.
Otherwise the slave instances will try to auto-register their account if
needed, but these accounts will lack the bot flag. Also, depending on the
lobby server configuration, auto-registration may fail if it requires a
validation code sent by email to finalize the registration. In this case you
will have to pre-register beforehand all the lobby accounts which could be
required by the cluster manager to start the slave instances, based on the
"nameTemplate" plugin setting.

Public instances VS private instances:
-------------------------------------
Clusters may contain two types of instances: public instances and private
instances. Public instances are non-passworded hosts automatically started by
the cluster manager. Private instances are passworded hosts, started on-request
by the cluster manager when a client uses the !privateHost command.
Clusters can contain public instances only, private instances only, or both
types of instances at the same time (depending on the cluster configuration).

Dependencies:
------------
- This plugin depends on the AutoRegister SPADS plugin, which must be loaded
before the ClusterManager plugin.
- For preferences data sharing between the instances, the Perl "DBD::SQLite"
module from CPAN is required. On Windows, main Perl distributions (ActivePerl
and Strawberry) already include this module in their package, so nothing needs
to be done. On Linux systems, this module may need to be installed manually. It
can be done easily either with your standard package manager (for example on
Debian-based systems: "apt-get install libdbd-sqlite3-perl"), either with a
Perl module manager such as cpanminus: "cpanm DBD::SQLite".

Caveats:
-------
- This plugin assumes the "varDir" global setting is the same for all the
instances (cluster manager instance and slave instances)
- For each instance started by the cluster manager, a subdirectory with the
name of the instance will be automatically created if needed in the
"%varDir%/ClusterManager" directory. This subdirectory will be used as the
"instanceDir" for this instance. A "log" subdirectory
("%varDir%/ClusterManager/%instanceName%/log") will also be created to store
all the logs of the instance.
- All the UDP ports between baseGamePort and baseGamePort+maxInstances-1
(included) must be unused and accessible from the outside (ports open on
firewall and forwarded if needed) so that the instances can host games
- All the UDP ports between baseAutoHostPort and
baseAutoHostPort+maxInstances-1 (included) must be unused on the loopback
interface