Need option to not include wrapper

[alerque]

Similar to #6, I am trying to use the output in the context of a system that understands what to do with the resulting inline markup. I don't want to wrap the document in <div id="wrapper"></div>. There should be a command line flag to now wrap the output. In fact I would argue that this should be the default, and adding a wrapper should be the option (similar to pandoc --standalone).