Update pear-MDB2_Driver_mysql package to 1.5.0b2.

1.5.0b3 2010-08-29 12:29 UTC

Changelog:

- fixed bug #15650: mysqli function used in setCharset()
- fixed bug #16003: incorrect check for error after mysql_store_result
- fixed bug #16147: first prepared statement is emulated when using factory
  with mysql
- fixed bug #16669: hostspec is ignored when protocol is unix
- fixed bug #17037: 'on update' not mentioned in tableInfo()
- fixed bug #17065: There is no NEW row in on DELETE trigger (fix error in FK
  constraint triggers)
- fixed bug #17650: lastInsertId can not handle bigint, forces cast to integer
  [alexpw]
- return ON UPDATE|DELETE action in getTableConstraintDefinition()

note:
- the multi_query test failes because this is not supported by ext/mysql

open todo items:
- use a trigger to emulate setting default now()

(taca)