Documentation: Add \nullptr macro and use where applicable

Qt for Python users reading the documentation assume that int(0) can
be passed for pointer parameters. Use the newly introduced \nullptr to
disambiguate this.

In a follow-up step, the \nullptr macro can be defined as None
when generating the Qt for Python documentation.

Task-number: PYSIDE-903
Change-Id: I3a45f87175a0668ab5f3f95f0aff409f7e3ef027
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>
Reviewed-by: Christian Tismer <tismer@stackless.com>
Reviewed-by: Venugopal Shivashankar <Venugopal.Shivashankar@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

0 files changed, 0 insertions, 0 deletions