Only call CM.focus() if CM is not already focused.
Fixing this->that.
Dont' force command mode in kbm.register_events.
Only call register_events on top level widget.
Rename _handle_new_view->_handle_display_view.
Merge pull request #4929 from ellisonbg/modal-fixes

Fixing various modal/focus related bugs

closes #4809
closes #4951