Bug fixes

36a1f41 1021538 dependencies updated
b844c08 all "var" -> "const" | "let", add Drafty.isValid() method
cc9ea51 enable setting human (UI) language
047f1ee fix for different order of messages
0cacd72 don't try to send note 'read' if there are no messages
426e860 fix for wrong [( / ) invalid content] message in new topics
1fdd590 bug: this.seq or this._maxSeq could be undefined
9131d55 fix for missing read notifications