Added support for multiple lines in button-like widgets

IPython/html/static/notebook/js/widgets/button.js

@@ -38,11 +38,12 b' define(["notebook/js/widget"], function(){'
         //          Frontent -> Frontend Sync
         update : function(){
             var description = this.model.get('description');
-            description.replace(' ', ' ')
+            description = description.replace(' ', ' ');
+            description = description.replace('\n', '<br>\n');
             if (description.length == 0) {
                 this.$el.html('&nbsp;'); // Preserve button height
             } else {
-                this.$el.html(this.model.get('description'));
+                this.$el.html(description);
             }
             
             return IPython.WidgetView.prototype.update.call(this);

IPython/html/static/notebook/js/widgets/selection.js

@@ -60,11 +60,12 b' define(["notebook/js/widget"], function(){'
         update : function(){
 
             var selected_item_text = this.model.get('value');
-            selected_item_text.replace(' ', ' ');
+            selected_item_text = selected_item_text.replace(' ', ' ');
+            selected_item_text = selected_item_text.replace('\n', '<br>\n');
             if (selected_item_text.length == 0) {
                 this.$droplabel.html('&nbsp;');
             } else {
-                this.$droplabel.html(this.model.get('value'));    
+                this.$droplabel.html(selected_item_text);    
             }
             
             var items = this.model.get('values');