- changed default logging to log file
- parametrized log file path
- added fluentd configuration
- introduced fluentd multi_format parser plugin

Currently error logs sent to syslog are represented
with severity ERROR, which is misleading for Notice
and Warning messages during service startup/shutdown.

Change-Id: I55106775fa54b412b50ecc10c12930445da15d03
Related-bug: PROD-21904 (PROD:21904)

The following configuration options added:

    galera_innodb_read_io_threads: 8
    galera_innodb_write_io_threads: 8
    galera_wsrep_slave_threads: 8
    galera_xtrabackup_parallel: 4
    galera_error_log_enabled: false

Change-Id: Id1185c3a38669c37dc88806b4e9955522629ce1c
Related-Bug: https://mirantis.jira.com/browse/PROD-16528

Make max_connections and innodb_buffer_pool_size configurable
through soft params instead of hard.

Change-Id: Id0bb8f6b6091289275864bf4dd6a6890d11b4782