mysql-test/lib/init_db.sql:
  remove definer from PK
mysql-test/r/events.result:
  update results
mysql-test/r/system_mysql_db.result:
  update results
mysql-test/t/events.test:
  remove I_S.EVENTS test and move it to events_grant.test
scripts/mysql_fix_privilege_tables.sql:
  change table definition
sql/event.cc:
  make events non-user specific (namespace change)
sql/event.h:
  make events non-user specific (namespace change)
sql/event_priv.h:
  make events non-user specific (namespace change)
sql/event_scheduler.cc:
  make events non-user specific (namespace change)
sql/event_timed.cc:
  make events non-user specific (namespace change)
sql/sql_parse.cc:
  make events non-user specific (namespace change)
sql/sql_show.cc:
  SHOW EVENTS is available to everyone who has EVENT on specific schema.
  No additional privileges are needed to see others' events.
  - user A has events in db1 and db2
  - user B has events in db1 and db3
  A will see all his events from db1 and db2 as well as B's events
  from db1 but not from db3.
  B will see her events from db1 and db3. In addition B will see
  only A's events from db1 but not db2.