htmlEscape our own outgoing messages

Not that sending arbitrary HTML isn't cool, but this was causing
messages like "<3" to get filtered at the recipient, and I want
to get this from my girlfriend. (Obviously my girlfriend and I are
speaking over encrypted chat. The NSA cannot know about our love.)
Format our own last message

It looks like this got disabled unnecessarily during an unrelated
change and never got re-enabled. We probably want to see the same
stuff as our chat partner sees, especially with regard to HTML tags,
so let's go ahead and re-enable it.