WL#1034 update

- fix EVENT_ACL problem that GRANT ALL on some_db.* to someone@somewhere did not get to mysql.db
- fix crash when the following is executed :
  CREATE EVENT P() CREATE EVENT E ON SCHEDULER 1 SECOND DO ROLLBACK;
  (creation works as well as calling P() which creates the event).


mysql-test/lib/init_db.sql:
  - fix init_db.sql so add Event_priv to the database privs, many tests failed because of that
    ommision
  - remove the quotes from the column names
mysql-test/t/events.test:
  - fix the small test, don't create own db
scripts/mysql_fix_privilege_tables.sql:
  - fix that
sql/event.cc:
  - be defensive and don't crash if outside has already has opened some table
sql/event_executor.cc:
  - show in SHOW PROCESSLIST - "event_scheduler" as name of the user of the main thread
  - use "localhost" as the host where event_scheduler comes from
  - comment out some debug info, fix other debug info
sql/event_timed.cc:
  - enable EVENT creation inside SP. sphead from lex->sphead goes to et->sphead. it's there only
    if we compile the event. OTOH when doing 
    CREATE PROCEDURE PROC() CREATE EVENT SOME_EV ON SCHEDULE EVERY 1 SECOND DO ROLLBACK;
    I have only to get the body of the event which is anonymous SP. Before it being "compiled"
    but then freed without being used because a bit later it is compiled one more time before
    being put in the events cache. So it was good that the memory structures weren't reused but
    scrapped out. Now lex->sphead is not needed during event creation but only where the event's
    body starts and where it ends so to be able at later stage to compile this anonymous SP (the
    body of the event).
sql/sp_head.cc:
  - copy over a fix to a crash
sql/sql_acl.h:
  - fix privileges.
    There was _NO_ documentation about that. Another CHUNK had to be created to so EVENT_ACL gets shifted to
    it's place in the db table. So how this is calculated? EVENT_ACL is 1 << 26. Remember 26, see which poistion
    in the db table is EVENT_ACL, it's 17, counted from 0. 26 - 17 = 9, then shift it with 9.
    CHUNKS are created because in some cases some privileges are in chunks and they are shifted at once. There are
    few chunks of such privileges which has to be shifted to get to exactly the structure of mysql.db table.
sql/sql_parse.cc:
  - ok, we don't care anymore about lex->sphead because our sphead is lex->et->sphead
sql/sql_yacc.yy:
  - bail out if new event_timed returns 0x0
  - enable creation of an event inside a SP
    CREATE PROCEDURE P() CREATE EVENT E ON SCHEDULE EVERY 1 SECOND DO SELECT 1;

scripts/mysql_fix_privilege_tables.sql

@@ -562,5 +562,6 @@ CREATE TABLE event (
 # EVENT privilege
 #
 
-ALTER TABLE mysql.user add Event_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL AFTER Create_user_priv;
-ALTER TABLE mysql.db add Event_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL;
+ALTER TABLE mysql.user add Event_priv enum('N','Y') character set utf8 DEFAULT 'N' NOT NULL AFTER Create_user_priv;
+ALTER TABLE mysql.db add Event_priv enum('N','Y') character set utf8 DEFAULT 'N' NOT NULL;
+