Revert color_map: do not derive from QObject to allow color map deepcopy

Author: PierreRaybaut

qwt/color_map.py

@@ -28,7 +28,7 @@
    :members:
 """
 
-from qtpy.QtCore import QObject, Qt, qIsNaN
+from qtpy.QtCore import Qt, qIsNaN
 from qtpy.QtGui import QColor, qAlpha, qBlue, qGreen, qRed, qRgb, qRgba
 
 
@@ -211,10 +211,8 @@ def colorIndex(self, interval, value):
         return 0
 
 
-class QwtLinearColorMap_PrivateData(QObject):
+class QwtLinearColorMap_PrivateData(object):
     def __init__(self):
-        QObject.__init__(self)
-
         self.colorStops = ColorStops()
         self.mode = None
 
@@ -324,10 +322,8 @@ def colorIndex(self, interval, value):
             return int(ratio * 255 + 0.5)
 
 
-class QwtAlphaColorMap_PrivateData(QObject):
+class QwtAlphaColorMap_PrivateData(object):
     def __init__(self):
-        QObject.__init__(self)
-
         self.color = QColor()
         self.rgb = QColor().rgb()
         self.rgbMax = QColor().rgb()