Add method to turn an AST into a string tree
Remove unneeded imports in MacroNode
Remove occurrencesBefore from the U2 check, and change thisKillsTheFormatting to use a collection
Don't allow a list start to be immediately followed by a newline
Make the Attachment rule more like WikiWords
Allow linebreaks before an escaped break when inline
Only render mailto: links as mailto links if there is no interwiki link called 'mailto'