Alan: moved your fields away, but reserved you a pointer.

Alan: moved your fields away, but reserved you a pointer.

Changed PDO::lastInsertId() to have following proto:

	string PDO::lastInsertId([string name])

this allows arbitrary unique identitifers to be returned from the driver.

The optional name parameter is for databases that require additional contextual
information to be able to return the correct identifier.  None currently use
it, but pgsql will be on the list of drivers that do.