Fixed issue #771.Comment allow new line.

Raising Fresh PR on issue #771 as my previous branch got messed up while pushing from local.
I have tested all scenarios from my end. 
The comment div is taking care of next line.
In case of edit it accepts new line and on hitting enter it goes to next line. to post the changed comments user will follow same ctrl+enter.
You are absolutely correct it should be enter_key. Not sure how I made this silly mistake. Might be dozed of while working at night. Will correct it.