QPageSize: mark ctors explicit

A QSize or QSizeF is not an accurate representation of a QPageSize, so
the corresponding constructor should be explicit.

Change-Id: I6b1808e5f93e3caef948c0e5300bd3c20e3c4210
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: John Layt <jlayt@kde.org>
QPageSize: make op== non-member

Better style, since it treats the left-hand and right-hand size symmetrically,
e.g. for implicit conversions.

Change-Id: If1ffa9dc2a018e402c884f60bfbc82e799daeb92
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
QPageSize: provide op!=

For consistency.

Change-Id: I4375a6f8c2514479a7479c735d397bf8a9876db1
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: John Layt <jlayt@kde.org>
QPageLayout: remove QPageLayout:: overqualifications

This is not Qt style, not needed, and clutters the code, so remove
QPageLayout:: qualifications where they're not needed.

Change-Id: I62f90c29bcb9f3c137d319051ac79e081fe5fb69
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: John Layt <jlayt@kde.org>
QPageLayout: use QExplicitlySharedDataPointer

Many setters check for an actual change before making changes to
data members, but because of QSharedDataPointer, the detach had
already happened by the time the comparison returned false.

Change-Id: I320806e74de4a64fa3a340831621c1f5120ebb0f
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: John Layt <jlayt@kde.org>
QPageLayout: make op== non-member

Better style, since it treats the left-hand and right-hand size symmetrically,
e.g. for implicit conversions.

Change-Id: Ib5d39b1ebffffcb664ee2f72c756702469e32d3b
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
QPageLayout: provide op!=

For consistency.

Change-Id: I20fb70999785e2c1947f033d63367a2f6746990a
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: John Layt <jlayt@kde.org>
QPageLayout: clean up operator==

The old code always compared the Private classes, unless one of them
was nullptr (which it never was, as there is no move ctor and all
other ctors create a QPageLayoutPrivate.

The new code compares the dpointers, and only if they differ, the
Private classes. It also drops the nullptr checks, as they cannot
trigger.

Change-Id: I523c3503e2edb520f98f9b4e2e3bdaf28a9a355d
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
QPageSize: clean up operator==

Recognize that the d-pointer can never be nullptr and drop the
nullptr checks.

The d-pointer can never be nullptr as there's no move ctor and all other
ctors create a QPageSizePrivate.

Change-Id: I6c4e165949ed55510aefbc2d933f20fc8e624333
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>