Preparation for a PySide version

	modified:   Bunch.py
	modified:   Callback.py
	modified:   Catalog.py
	modified:   Datasrc.py
	modified:   FitsImageCanvas.py
	modified:   Future.py
	modified:   GingaPlugin.py
	modified:   ModuleManager.py
	modified:   PythonImage.py
	modified:   Task.py
	modified:   gtkw/ColorBar.py
	modified:   gtkw/FileSelection.py
	modified:   gtkw/FitsImageCanvasGtk.py
	modified:   gtkw/FitsImageCanvasTypesGtk.py
	modified:   gtkw/GtkMain.py
	modified:   gtkw/PluginManagerGtk.py
	modified:   gtkw/Readout.py
	modified:   gtkw/example1.py
	modified:   gtkw/example2.py
	modified:   gtkw/plugins/Catalogs.py
	modified:   gtkw/plugins/Contents.py
	modified:   gtkw/plugins/Drawing.py
	modified:   gtkw/plugins/Errors.py
	modified:   gtkw/plugins/Header.py
	modified:   gtkw/plugins/Log.py
	modified:   gtkw/plugins/Ruler.py
	modified:   gtkw/plugins/WBrowser.py
	modified:   misc/plugins/RC.py
	modified:   qtw/ColorBar.py
	modified:   qtw/FitsImageCanvasTypesQt.py
	modified:   qtw/FitsImageQt.py
	modified:   qtw/GingaQt.py
	modified:   qtw/Plot.py
	modified:   qtw/PluginManagerQt.py
	modified:   qtw/QtHelp.py
	modified:   qtw/QtMain.py
	modified:   qtw/Readout.py
	modified:   qtw/example1.py
	modified:   qtw/example2.py
	modified:   qtw/plugins/Catalogs.py
	modified:   qtw/plugins/Contents.py
	modified:   qtw/plugins/Cuts.py
	modified:   qtw/plugins/Debug.py
	modified:   qtw/plugins/Drawing.py
	modified:   qtw/plugins/Errors.py
	modified:   qtw/plugins/FBrowser.py
	modified:   qtw/plugins/Header.py
	modified:   qtw/plugins/Histogram.py
	modified:   qtw/plugins/IRAF.py
	modified:   qtw/plugins/Info.py
	modified:   qtw/plugins/Log.py
	modified:   qtw/plugins/MultiDim.py
	modified:   qtw/plugins/Pan.py
	modified:   qtw/plugins/Pick.py
	modified:   qtw/plugins/PixTable.py
	modified:   qtw/plugins/Preferences.py
	modified:   qtw/plugins/Ruler.py
	modified:   qtw/plugins/Thumbs.py
	modified:   qtw/plugins/WBrowser.py
	modified:   qtw/plugins/Zoom.py
	modified:   qtw/tests/cbar_test.py
	modified:   util/colorramp.py
	modified:   util/grc.py
	modified:   wcs.py

- all Qt modules except QtHelp are modified to import Qt bindings from
    QtHelp
- defined QString so that it can be redefined to str
- removed some comment lines in headers of files so that they don't
    keep causing git conficts every time I edit the file