Redefine CPU_xx constants in cv::namespace

This makes them visible from the python bindings
Fix mouse handling in python demos
GSoC Python Tutorials
GSoC Python Tutorials

removed white spaces

removed blank lines at EOF

removed duplicate labels
Replace obsolete Gtk symbols

This update replaces depreciated Gtk1.x symbols with Gtk2.x symbols in
preparation for adding Gtk3 support. These edits aim to be fully
compatible with Gtk2.x, allowing backward compatibility.

The following symbols have been replaced in this commit:

Gtk symbols that have been moved to the Gdk library:
 - GtkType -> Gtype
 - GTK_CHECK_CAST -> G_TYPE_CHECK_INSTANCE_CAST
 - GTK_CHECK_TYPE -> G_TYPE_CHECK_INSTANCE_TYPE
 - gtk_signal_connect -> g_signal_connect
 - GTK_SIGNAL_FUNC -> G_CALLBACK
 - gtk_type_class -> g_type_class_peek
 - gtk_type_new-> g_object_new
 - GtkTypeInfo -> GtypeInfo (Not required for
   g_type_register_static_simple)
 - gtk_type_unique -> g_type_register_static_simple
 - gdk_draw_image_rgb -> replaced by gdk_cairo_source_pixbuf
   NB: This requires porting to use cairo contexts and GdkPixbufs.

The following gtk symbols are changed for their modern equivalent:
 - GTK_WIDGET_REALIZED -> gtk_widget_get_realized
 - GTK_OBJECT_FLAGS -> gtk_widget_set_realized

Symbols without replacement:
 - gtk_range_set_update_policy -> No replacement; as default policy is
   set to continuous we can delete this line.
erGrouping now uses a classifier for group validation instead of a set of heuristical ifos.
Updated documentation and sample to use the new function API
Merge pull request #1520 from lluisgomez:scene_text_erGrouping_classifier
Merge remote-tracking branch 'upstream/master'
Merge pull request #1488 from abidrahmank:py_tutorials
Merge pull request #1477 from nzjrs:python-gethardwaresupport
Merge pull request #1429 from nzjrs:fix-sketcher
Change true for TRUE

The second parameter of gtk_widget_set_realized is of type gboolean
(gint). This is to ensure compatibility on alternative compilers and
platforms.
Merge pull request #1512 from Exocoder:pre-gtk3
Merge remote-tracking branch 'upstream/master'