The plaintext representation of the rich reply example from #5969 ended up
looking like this:

&Adam: > TravisR: > Welcome Back Bot: > Welcome back, @richvdh:sw1v.org beep So what does a reply to a reply look like? Oh boy... 

This isn't at all helpful to clients that aren't html-aware. Maybe it's only the
first message that gets > style quotes. Maybe it's specific to m.notice
messages. Either way, it's confusing.