code: function (event, callback) {
              // (To learn how the handlers object works, see inline comment at Crafty.bind)
              var hdl = handlers[event], i, l, global_callbacks, found_match;
  
              if (hdl === undefined || hdl['global'] === undefined
                                             || hdl['global'].length === 0) {
                  return false;
              }
  
              // If no callback was supplied, delete everything
              if (arguments.length === 1) {
                  delete hdl['global'];
                  return true;
              }
  
              // loop over the globally-attached events
              global_callbacks = hdl['global'];
              found_match = false;
              for (i=0, l=global_callbacks.length; i < l; i++) {
                  if (global_callbacks[i] === callback) {
                      found_match = true;
                      global_callbacks.splice(i, 1);
                      i--;
                  }
              }
              return found_match;
          }
docs: @
  #Crafty.unbind
  @category Core, Events
  @sign public Boolean Crafty.unbind(String eventName, Function callback)
  @param eventName - Name of the event to unbind
  @param callback - Function to unbind
  @sign public Boolean Crafty.unbind(String eventName, Number callbackID)
  @param callbackID - ID of the callback
  @returns True or false depending on if a callback was unbound
  Unbind any event from any entity or global event.
  @example
  ~~~
  var play_gameover_sound = function () {...};
  Crafty.bind('GameOver', play_gameover_sound);
  ...
  Crafty.unbind('GameOver', play_gameover_sound);
  ~~~
  
  The first line defines a callback function. The second line binds that
  function so that `Crafty.trigger('GameOver')` causes that function to
  run. The third line unbinds that function.
  
  ~~~
  Crafty.unbind('GameOver');
  ~~~
  
  This unbinds ALL global callbacks for the event 'GameOver'. That
  includes all callbacks attached by `Crafty.bind('GameOver', ...)`, but
  none of the callbacks attached by `some_entity.bind('GameOver', ...)`.