Qpageview

* Maintainance release
* Kept another implicit float->int conversion from happening by having
Scrollarea.remainingScrollTime() returning an int
* Some robustness improvements
* Documentation improvements

* View.strictPagingEnabled always lets PgUp/PgDn scroll a page instead
of a screenful
* Don't depend on implicit float->int conversions, which were deprecated since
Python 3.8 and not supported anymore by Python 3.10
* Fixed initial zoomfactor for ImageView when fitNaturalSizeEnabled is True

* added view.View.pages() method (2)
* added view.View.setPages() method (inspired by 4)

* Many documentation updates
* Add PagerAction.setButtonSymbols()
* fix flickering mouse cursor on rubberband
* make it easier to manipulate the edge/corner of the rubberband

Initial release. The qpageview module was developed by me, Wilbert Berendsen,
as a replacement of the qpopplerview module inside Frescobaldi, the LilyPond
sheet music text editor. I decided that it would be best if qpageview became
its own project, to make it easier to use this package in other applications.