add ^M-O for toggling output scroll

IPython/frontend/html/notebook/static/js/codecell.js

@@ -214,6 +214,11 b' var IPython = (function (IPython) {'
     };
 
 
+    CodeCell.prototype.toggle_output_scroll = function () {
+    this.output_area.toggle_scroll();
+    };
+
+
     CodeCell.prototype.set_input_prompt = function (number) {
         this.input_prompt_number = number;
         var ns = number || " ";

IPython/frontend/html/notebook/static/js/notebook.js

@@ -191,7 +191,11 b' var IPython = (function (IPython) {'
                 return false;
             } else if (event.which === 79 && that.control_key_active) {
                 // Toggle output = o
-                that.toggle_output();
+                if (event.shiftKey){
+                    that.toggle_output_scroll();
+                } else {
+                    that.toggle_output();
+                }
                 that.control_key_active = false;
                 return false;
             } else if (event.which === 83 && that.control_key_active) {
@@ -865,6 +869,12 b' var IPython = (function (IPython) {'
     };
 
 
+    Notebook.prototype.toggle_output_scroll = function (index) {
+        var i = this.index_or_selected(index);
+        this.get_cell(i).toggle_output_scroll();
+    };
+
+
     Notebook.prototype.collapse_all_output = function () {
         var ncells = this.ncells();
         var cells = this.get_cells();