Fix message classes for history items
Review Request #128841 - Created Sept. 5, 2016 and submitted
"incoming" and "outgoing" classes for history messages are swapped - they are used for local to remote and remote to local messages, respectively. This bug is visible in styles that use a single .html file for sent and received messages, relying on a class. I don't know which theme could be used to test it - I spotted this while playing with theme creation. Everything without an "Outgoing" directory and with distinguishable incoming/outgoing messages should be ok.
- compile/run: OK - talk with someone, close the window, open the chat again, check the last chat message's direction: OK