updated md slide separator regex #929
updated md slide separator regex #929

see https://github.com/hakimel/reveal.js/issues/929#issuecomment-80738837

leesdolphin/language-punctuation,kayakr/ndf2015,leesdolphin/why-python-is-awesome,leesdolphin/why-python-is-awesome,leesdolphin/language-punctuation,leesdolphin/language-punctuation,leesdolphin/why-python-is-awesome,kayakr/ndf2015,kayakr/ndf2015