Improve detection of quotes at the bottom of messages
Geary should try to detect and fold quotes at the bottom of email, so that people top-posting aren't breaking the flow of the conversation viewer (see for example #212 (closed)).
This is in particular an an issue for people using Outlook Outlook.com and GMail, so it would be good to work out if there is any way of detecting the quoted parts sent by those providers so we can mark them as quotes.