Fix user color when submitting new message

Right now, when the user submits a new message in an ongoing conversation, the user color circle is not showing. The reason is that the user color value is not created due to the user name string having an extra space at the end. This causes the user string to be not matched up with the user string in the list of users, where the original colors are stored. 

I couldn't figure out why the extra space is added to ``$currentShape.text()`` on line 80, but I did managed to fix the problem by using the ``$.trim`` function to remove the extra space.

Update: for the ``<br />`` tags creating the line breaks, for some reason they are not being recognized as proper html. So I've opted to use ``\n`` to make the change happen.
Very interesting!  It looks like the strange behavior with `<br>` tags and \n originates here, and relates to line 162.  When a newline is entered by the user into the textarea, it looks like they show up as '\n' when we use `$('textarea').val()` on line 152.  Originally, the code before seemed to replace all '\n' newlines with a `<br />` tag.  I'm not sure why this was the case, looking back.  If newlines are replaced with the br's in the message variable, then on line 162, we will create a `<p>` tag whose inner text includes the `<br>` tag, which we don't want.

Tony, you found that \n produces the behavior that we do want.  I think this is great news because we probably don't need to include this line 153 at all.  If we want the \n and 153 tries to replace \n with \n, we could probably remove it and its related comment.

If we get the right behavior after removing the .replace, then I think it LGTM!