The monitor will now also create the database if it is missing. Since it
already creates the table, also creating the database is not a large
addition.
Cleaned up some of the related checking code and combined them into a
simple utility function.
Time elapsed is now properly tracked during a switchover. After slave
redirection, an event is added to the master. Then, the slaves are queried
repeatedly until they advance to the newest event. I/O and SQL errors are
also detected.
During switchover, MASTER_GTID_WAIT is now called on all slaves. This causes
switchover to complete slower than before but is safer if log_slave_updates
is not on on the new master server. Also, read_only is disabled on the
demoted server if waiting on slaves or promotion fails. This should
effectively cancel the failover for the old master.
'mysqlmon' is still accepted but 'mariadbmon' is loaded instead.
This is done at runtime instead of e.g. by using a symbolic link,
so that a warning can be logged.
The warning is logged and the translation of the module name is
made by the code that loads the modules so that it's easy to do
the same thing for other modules as well.
In a subsequent commit the documentation is updated.
