Add a conversation callout style
Add a conversation callout style

fixes #577
binford2k/showoff,puppetlabs/showoff,puppetlabs/showoff,marrero984/showoff,puppetlabs/showoff,marrero984/showoff,marrero984/showoff,slambert/showoff,slambert/showoff,binford2k/showoff,binford2k/showoff,slambert/showoff,puppetlabs/showoff,binford2k/showoff,marrero984/showoff,slambert/showoff