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.
Oh sorry forgot to answer that. I have created the border dotted as saw few other applications where in case of edit its dotted. So do you want me to change it?

Regarding the width I couldn;t understand,how much should I set. Shall I keep it as 95%. Or some minimum like 50%. Or you meant to get rid of max-width