* Two problems here:
** Now WITH_PERFSCHEMA_STORAGE_ENGINE is not set we were assuming the installed sys schema version was always 1.0.0, removed this now
** Also FLUSH PRIVILEGES after creating the user, so it is available straight away

Bug#21935210 MYSQL.SYS@LOCALHOST HAS TRIGGER PRIVILEGE ON THE WHOLE INSTANCE
* Removed global TRIGGER, and added only on the sys schema

Bug#21966366 SYS: PROVIDE A WAY TO ALLOW FOR LOCAL CUSTOMISATIONS
* Rather than check for equality of counts, check for at least as many as expected (but allow more or equal)

Sneak in a typo fix (s/procdure/procedure/) in the execute_prepared_stmt comment.

Reviewed-by: Georgi Kodinov <georgi.kodinov@oracle.com>
Reviewed-by: Marc Alff <marc.alff@oracle.com>
RB: 10567
(cherry picked from commit dde827eccabfc5d8954977d0251b7dba3cce8342)