Fix some base classes for pi documentation files

etg/_stc.py

@@ -62,6 +62,7 @@ def run():
     
     c = module.find('wxStyledTextCtrl')
     assert isinstance(c, etgtools.ClassDef)
+    c.piBases = ['wx.Control', 'wx.TextEntry']
     tools.fixWindowClass(c, False)
     module.addGlobalStr('wxSTCNameStr', c)
     

etg/_xml.py

@@ -83,6 +83,7 @@ def run():
     
         
     c = module.find('wxXmlDocument')
+    c.piBases = ['wx.Object']
     c.find('GetEncoding').ignore()
     c.find('SetEncoding').ignore()
     

etg/_xrc.py

@@ -74,6 +74,7 @@ def run():
     
     c = module.find('wxXmlResource')
     assert isinstance(c, etgtools.ClassDef)
+    c.piBases = ['wx.Object']
     c.addPrivateCopyCtor()
 
     # Add a bit of code to the ctors to call InitAllHandlers(), for