Add selection widget

IPython/html/widgets/selection/model.js

@@ -0,0 +1,2 @@
+var SelectionWidgetModel = IPython.WidgetModel.extend({});
+IPython.notebook.widget_manager.register_widget_model('SelectionWidgetModel', SelectionWidgetModel);

IPython/html/widgets/selection/widget.py

@@ -0,0 +1,15 @@
+import os
+
+from ..widget import Widget
+from IPython.utils.traitlets import Unicode, List, Bool
+from IPython.utils.javascript import display_all_js
+
+class SelectionWidget(Widget):
+    target_name = Unicode('SelectionWidgetModel')
+    default_view_name = Unicode('DropdownView')
+    _keys = ['value', 'values', 'disabled']
+
+    value = Unicode()
+    values = List() # List of values the user can select
+    disabled = Bool(False) # Enable or disable user changes
+