New QPageSize class to encapsulate paper sizes and names to ensure all
sizes and conversions are consistent and match the Postscript standard
sizes.
Subsequent changes will use this class in the paged paint devices,
paint engines, print engines, and print plugins to replace multiple
inconsistent local implementations.
[ChangeLog][QtGui][QPageSize] Added new QPageSize class to implement
Adobe Postscript PPD standard page sizes. This class supports the
standard page sizes, names and keys from the PPD standard, and provides
convenient size and rect conversion methods.
Change-Id: Ie2c8be0c3df0d29ac5da4cd9877ad41d0982633c
Reviewed-by: Lars Knoll <lars.knoll@digia.com>