Fix the docs on when setDocument() deletes the previous document

Change-Id: I08d162a1c1e1765213205e63183ed75b2491374d
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Doc: corrected description of QTableWidget::clear()

Task-number: QTBUG-36329
Change-Id: I3a78311bcb076b414ecf1ecf866e4ed60c391126
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Fix printing with a custom paper specified.

If DMPAPER_USER is set from the print dialog then it is expected that
the specific member variables to get the custom width and length are
used. The size returned by querying the DC_PAPERSIZE is some random
default and is not the one actually requested by the user.

Also ensure that when it is a custom paper size from the driver
itself that we store the right paper size.

Change-Id: I760b8429ca1b01f5e303f2111b8d7ca1795c8ab8
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>