support mysql 8 TimeZone Changes and Master User Creation

[timo11]

[timo11]

due to a bug in the jdbc library, servers running mysql 8 may need timezone configuration.
My server, when it determined its timezone from the operating system, caused jdbc to throw errors about 'CDT' being an invalid timezone.
Switching my os time to GMT fixed the problem.
More reasonably, possibly, adding "default-time-zone=-5:00" (CDT by numbers) to my my.cnf file also resolved the issue.

[timo11]

'populating the time zone tables', described at https://dev.mysql.com/doc/refman/8.0/en/time-zone-support.html does not eliminate the need to configure the timezone for the server, but it does make it possible to use names rather than numbers, e.g. "default-time-zone=America/Chicago".