Merge branch 'username-in-comments' into 'master'

Username in comments

Its hard to mention person in comment if you don't know his username.
This patch show person username right after his name in comment row

See merge request !1281

app/views/projects/notes/_note.html.haml

@@ -18,6 +18,8 @@
               %i.fa.fa-trash-o.cred
               Remove
         = link_to_member(@project, note.author, avatar: false)
+        %span.author-username
+          = '@' + note.author.username
         %span.note-last-update
           = note_timestamp(note)