Fixes `header': wrong number of arguments (3 for 2)
Merge branch 'zimbatm/bug/header-args' into patch
GH-17: escape macros, quotes, and hyphens in code

Thanks to zimbatm for reporting this issue.
Merge branch 'patch'
Version 2.0.4 (2014-04-26)
upgrade to Redcarpet 3.1 which adds header anchors