style markdown in-place

[jancborchardt]

Rather than being a 2-pane editor, the Markdown mode should format the elements in place (much like http://iawriter.com ).
When a line starts with a #, that line is then styled as heading one (and still has the pound in front of it). Likewise with * for lists, and links should also be autolinked.

[bergie]

Markdown editing isn't a direct feature of Hallo, but instead something built on top. That said, it could easily become a set of plugins at some point. This could be done together with #11, and would be made easier by the implementation of #5.