GFM Refactoring
Created by: rspeicher
According to cane, the gfm helper method was by far the most complex method in the entire project, so I tried to refactor it a bit.
I think the new one is a bit easier to understand and will be easier to maintain, especially for the regex pattern.
This also shows that there's still lots of room for improvement, particularly removing the duplication from dealing with html_options and the various link classes. I'll reply to this with some ideas.