Fixes in floating dates with migrated histories.

All service messages are now not multiline (including pinned).
Confirmation for profile photo deleting will be added (not enabled).
Copy-by-selection should be supported in Linux version now.
Drafts that contain only reply-to-id (without text) support added.

Telegram/SourceFiles/overviewwidget.cpp

@@ -730,6 +730,8 @@ void OverviewInner::clear() {
 	}
 	_layoutDates.clear();
 	_items.clear();
+
+	App::clearMousedItems();
 }
 
 int32 OverviewInner::itemTop(const FullMsgId &msgId) const {