Bug #15187 Triggers: names are case sensitive

Description:
The MySQL Reference Manual says:
"Column, index, stored routine, and trigger names are not case
sensitive on any platform, nor are column aliases."
But if I create a trigger named A, I can't drop a trigger named a,
I have to drop a trigger named A.

How to repeat:
mysql> CREATE TABLE t (s1 INT);
Query OK, 0 rows affected (0.01 sec)

mysql> CREATE TRIGGER A BEFORE INSERT ON t FOR EACH ROW SET @a = @a;
Query OK, 0 rows affected (0.01 sec)

mysql> DROP TRIGGER a;
ERROR 1360 (HY000): Trigger does not exist
mysql> DROP TRIGGER A;
Query OK, 0 rows affected (0.00 sec)

miguel@hegel:~/dbs/5.0> bin/mysql -uroot test
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5 to server version: 5.0.17-debug

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> CREATE TABLE t (s1 INT);
Query OK, 0 rows affected (0.01 sec)

mysql> CREATE TRIGGER A BEFORE INSERT ON t FOR EACH ROW SET @a = @a;
Query OK, 0 rows affected (0.01 sec)

mysql> DROP TRIGGER a;
ERROR 1360 (HY000): Trigger does not exist
mysql> DROP TRIGGER A;
Query OK, 0 rows affected (0.00 sec)

I've updated the documentation.

Re-assigning to  Dmitri and setting the lead to Konstantin.