Add support to QPdfWriter for QPageSize, QPageLayout, and resolution.
[ChangeLog][QtGui][QPdfWriter] The QPdfWriter now supports setting
the PDF orientation, layout and resolution by using QPageSize and
QPageLayout.
Change-Id: I9c269f997ec540dac1989f355c6a2e7488947966
Reviewed-by: Lars Knoll <lars.knoll@digia.com>