Mentions will now work with all legal chars

As the server has been updated to enforce username rules, we can now
check for the next position of whitespace. This allows ALL users to have
a working mention system. Currently "-" is available for users, this
will fix that.

cockatrice/src/chatview.cpp

@@ -247,7 +247,7 @@ void ChatView::appendMessage(QString message, QString sender, UserLevelFlags use
                     showSystemPopup(ref);
                 }
             } else {
-                int mentionEndIndex = message.indexOf(QRegExp("\\W"), 1);// from 1 as @ is non-char
+                int mentionEndIndex = message.indexOf(QRegExp("\\s"), 1);// from 1 as @ is non-char
                 if (mentionEndIndex == -1)
                     mentionEndIndex = message.size(); // there is no text after the mention
                 QString userMention = message.left(mentionEndIndex);