PyQt 4.11 compatibility

Starting in PyQt 4.11, there is no pyqtconfig, so this patch imitates it when its not found.
pyqtconfig.QtGuiModuleMakefile simply calls sipconfig.SIPModuleMakefile with qt=['QtCore', 'QtGui'],
thus this patches has no effect if pyqtconfig is found (i.e. if the user has PyQt <=4.10)