When someone mentions another person in discuss/chat window, the
mentioned name was displayed just as a text, which may be unclear. With
this commit, we display mentions with the same style as mentions in a
message.
To do that, the main idea is to change the input by a div with
contenteditable set to true. This allows us to add <a>...</a> inside.
Nikunj Ladava
c778de44c7