QSqlError: Set error code for psql-driver.

Task-number: QTBUG-142
Change-Id: I4a68da595b7c8869188225958eaa88f789d4c3bf
Reviewed-by: Mark Brand <mabrand@mabrand.nl>
Add deleteItems(), needed by QtQuick.Layouts

(Picked from QGridLayoutEngine in qtquickcontrols)

Change-Id: Ieb00f7fb0166669e6831f3d3dbe3a9ef78b57453
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>