[PyQt] Qt message handler has wrong signature with Qt5

[Baz Walter]

Hello

For Qt4, QtCore.qInstallMsgHandler installs a Qt message handler with 
the following signature:

     void myMsgHandler(QtMsgType, const char *);

Using PyQt4 with Qt4, this correctly results in the second argument 
being passed as a python bytes object (for both the v1 and v2 apis).

However, for Qt5 it only does this when using Python3 with the v2 api. 
For Python3 with the v1 api, it passes a QString, and for Python2 it 
either passes a QString (v1 api) or a python unicode object (v2 api).

I realize that QtCore.qInstallMsgHandler has been deprecated in Qt5, but 
it would still be great if this could be fixed at some point.

Simple test script:

     import sys, sip
     sip.setapi('QString', int(sys.argv[1]) if sys.argv[1:] else 1)
     from PyQt4 import QtGui, QtCore

     app = QtGui.QApplication([])

     def handler(kind, msg):
         print('API v%s: %s, %s' % (
             sip.getapi('QString'), type(kind), type(msg)))

     QtCore.qInstallMsgHandler(handler)
     app.desktop().screenGeometry(None)

-- 
Regards
Baz Walter