[PyQt] PyQt v5.5 Release Candidate

[Phil Thompson]

The current PyQt5 and SIP snapshots can be considered as release 
candidates. The final releases should be around the end of this week.

The QtLocation and QtNfc modules have been added. The QProxyStyle, 
QMacToolBar and QMacToolBarItem classes have been added.

For the moment the Qt3D modules have not been implemented - the 
documentation in Qt v5.5.0 is too incomplete.

There are also issues with Qt v5.5.0 on OS X - see the documentation for 
the details.

Phil